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PubMed1999

[A case of arteriovenous fistula of the lung].

A 29-year-old male was admitted to our hospital for further evaluation of left sided paresis, cyanosis, clubbing finger. The laboratory data revealed polycythemia and hypoxemia. Cerebralarteriogram showed right middle cerebral artery occulusion. Cardiofunctional test showed atrial fibrillation, lower left ventricular function. Cardiac catheterization, pulmonary arteriography and three dimensions CT were performed. Right to left shunt rate was 20.4%. A single large pulmonary arteriovenous fistura with a feeding artery (A10) and a draining vein (V10) was found clearly. In this cases, arteriovenous fistula was large, blood flow was thought to be rapid. We thought transcatheter embolization was not useful. And we performed right lower lobectomy. Postoperative course was not eventful. Cyanosis disappeared, clubbing finger was cured.

Adult↗
PubMed2002

Effects of chronic, rapid right atrial pacing on cardiac hemodynamics and myofibrillar ATPase activity in piglets.

OBJECTIVES: To determine whether chronic, rapid right atrial pacing in newborn neonatal piglets has any effects on cardiac hemodynamics, and whether these changes are associated with intrinsic alterations in cardiac contractile potential as shown by cardiac myofibrillar calcium ATPase activity. BACKGROUND: Although many studies have examined aspects of heart function in models of supraventricular tachycardia, far less is known about its effects in neonatal animals. It is thought that rapid pacing induces a dilated cardiomyopathy in immature pigs. ANIMALS AND METHODS: Two-week-old piglets underwent rapid right atrial pacing (250 beats/min) for 10 days, and their cardiac hemodynamic response was monitored. To obtain subcellular mechanistic information regarding systolic dysfunction, cardiac myofibrils were isolated and calcium adenosine triphosphatase activity was measured. RESULTS: Control piglets had a heart rate of 185 beats/min at the end of the experimental period. Pulmonary artery flow, pulmonary artery flow index and left ventricular end-diastolic diameter were unchanged as a function of rapid, chronic right atrial pacing. Aortic pressure decreased in the paced piglets. Left atrial pressure increased approximately threefold in the paced animals. Left ventricular end-systolic diameter was also significantly higher after pacing, but left ventricular end-diastolic diameter was unchanged. Left ventricular shortening fraction was depressed approximately 50%. Myofibrillar calcium adenosine triphosphatase activity was significantly depressed as a function of pacing. CONCLUSIONS: Neonatal piglets undergoing chronic supraventricular tachycardia exhibit systolic dysfunction in the absence of dilation. The depression in contractile protein calcium adenosine triphosphatase activity provides information at a subcellular level regarding the mechanism responsible for this cardiomyopathy.

Adenosine Triphosphatases↗
PubMed1990

Atrialization of right ventricular pressure during acute cardiac allograft rejection.

We describe a patient who, during an episode of acute cardiac rejection, developed such severe systolic dysfunction that there was transient near-adynamic function of the right ventricle. This right ventricular dysfunction was reflected hemodynamically by the unusual finding of atrialization of right ventricular pressures. The patient's cardiac function returned to normal after treatment with extensive immunotherapy.

Acute Disease↗
PubMed1987

[Comparative study of auricular stimulation by transesophageal and endocavitary approach for evaluating sinus and atrioventricular node function].

The purpose of this study was to find out whether non-invasive transoesophageal pacing could effectively replace right intra-atrial pacing for the indirect evaluation of sinus node and atrioventricular (AV) node function. In a population of 17 patients the corrected sinus node recovery time (CSRT), the atrio-sinu-atrial conduction time (ASACT) and Wenckebach's point (W) were calculated by intracavitary pacing, then by transoesophageal pacing. There was no significant difference between the two methods in pre-pacing sinus cycle. With right intra-atrial pacing, mean CSRT value was 365 +/- 54 ms (with 5 values greater than 520 ms), mean ASACT value was 229 +/- 29 ms (with 8 values greater than 220 ms), and W occurred at a mean cycle length of 425 +/- 29 ms. With transoesophageal pacing, mean CSRT value was 406 +/- 87 ms (with 5 values greater than 520 ms), mean ASACT value was 222 +/- 17 ms (with 8 values greater than 220 ms), and W occurred at a mean cycle length of 408 +/- 26 ms. The two methods correlated very closely for CSRT and W (r = 0.97) and relatively well for ASACT (r = 0.84). The number of CSRT and ASACT values regarded as prolonged was the same with the two methods; 84% of recorded (i.e. maximal) CSRT values occurred with the same length of pacing cycle. There was no statistically significant difference between the two methods in the calculation of CSRT and ASACT, but W occurred at a slightly shorter cycle (p less than 0.05) with transoesophageal pacing. Thus, transoesophageal pacins is a non-invasive, easy to perform method for indirect exploration of sinus node and AV node function in patients who do not require subnodal conduction studies.

Aged↗
PubMed2003

Atrial compartment operation for atrial fibrillation: to isolate the left atrium or not?

BACKGROUND: The atrial compartment operation was designed to convert atrial fibrillation (AF) to sinus rhythm with intentional preservation of the electrical connection between adjacent atrial compartments. However, incidental left atrial isolation was observed in some patients. This study compared the long-term clinical outcomes of left atrial isolation for AF with those with right and left atrial connection. METHODS: Twenty patients with mitral valve disease and chronic AF who underwent atrial compartment operation with successful sinus conversion were studied. Left atrial isolation was documented by local electrogram recording. When there were no signs of electrical connection between the left atrium and the rest of the heart, either during sinus rhythm or during stimulation from various atrial compartments, left atrial isolation was confirmed. All patients were followed by electrocardiogram and echocardiogram serial recordings. Clinical signs and symptoms of cardiac performance and thromboembolism were also examined. RESULTS: Seven patients showed an isolated left atrium and 13 patients had electrical connection between the right and left atria. The age, gender, AF duration, and underlying disease were not different between the two groups of patients. During a mean follow-up period of 66 +/- 15 months, none of the patients with left atrial isolation showed recurrence of AF, although one experienced paroxysmal atrial flutter. However, 8 of the 13 patients with right and left atrial connection experienced recurrent atrial flutter/fibrillation (6 atrial flutter and 5 AF) (p = 0.058). The propensity for recurrent atrial flutter/fibrillation in these patients may be related to the conduction delay between the two atrial compartments, measured at 142 +/- 48 ms. At the end of the follow-up period, all patients with left atrial isolation remained in normal sinus rhythm without antiarrhythmic drugs. Of the patients who had right and left atrial connection, 2 developed sustained AF and 1 developed atrial flutter. Patients with left atrial isolation showed a decreased transmitral "A" flow compared with those with right and left atrial connection. Postoperative left atrial diameter and clinical functional class did not differ between patients with and without left atrial isolation. The incidence of embolization observed in both treatment groups did not differ significantly: 14% (1/7) in patients with left atrial isolation and 8% (1/13) in patients with right and left atrial connection (p > 0.05 between the groups). CONCLUSIONS: Left atrial isolation confers a better arrhythmia outcome but at the expense of poorer mechanical performance as compared with preserved electrical connection between the two atria. Nonetheless, all patients remain at risk for systemic embolization. Therefore, modifications of current surgical incisions for AF are needed.

Adult↗
PubMed2000

Ebstein's malformation. surgical treatment and results.

Ebstein's malformation can be defined as an anomaly of the tricuspid valve existing in the setting of a right ventricular dysfunction. The technique introduced by Carpentier in 1980 is based on the concept of mobilization of the restrictive anterosuperior leaflet associated with a longitudinal plication of the inlet component of the right ventricle. From January 1980 to December 1999, 142 patients underwent surgery. The mean age was 25 +/- 15 years (1-65). Cyanosis was present in 48% and associated lesions in 64% of the patients. Patients were classified using a functional approach according to the severity of the lesions. Mild displacement of the septal leaflet, along with small size of the atrialized chamber was seen in 5% (referred to as Type A). Massive displacement of the septal leaflet, but with normal motion of the anterosuperior leaflet and an extensive atrialized chamber, was seen in 35% (Type B). In 51%, the mural (inferior) leaflet was absent, the anterosuperior leaflet was severely restricted by muscular trabeculations and very short tendinous cords, and the anterolateral papillary muscle was incorporated in the right ventricular wall. In these patients (Type C), the atrialized chamber was markedly enlarged and had dyskinetic walls. In such cases, the contractility of the distal (functional) right ventricle was also impaired, and some degree of stenosis of the tricuspid valve was present in one-fifth of them. In the most severe cases (8%), the leaflet tissue of the valve was extremely reduced and the right ventricular walls were thin and contracted poorly. This resulted in the so-called tricuspid sack arrangement (Type D). Valve replacement was needed in only 4 cases, with conservative surgery being achieved in 138 patients by means of mobilization of the anterosuperior leaflet and longitudinal plication of the inlet component of the right ventricle. Additional procedures included the use of a prosthetic ring (94 patients) and partial Glenn anastomosis (30 patients). The hospital mortality was 10%, mainly due to acute postoperative right ventricular failure. Actuarial survival was 75% at 10 years. After operation, 94% of the patients were in functional class I or II of the New York Heart Association, and 88% had no or mild tricuspid valve insufficiency as judged by echocardiography. The rate of reoperation was 9% with a mean delay of 3 years. A second repair was performed in 5 patients. Freedom from reoperation was 87% at 10 years. Sinus rhythm was present in 81%, and 8 pacemaker devices were implanted, 5 for surgically induced atrioventricular block, and 3 because of preoperative conduction disturbances. The use of the partial Glenn anastomosis was introduced recently in cases where the right ventricular contractility was severely impaired, and/or tricuspid valve repair was difficult, and/or permanent atrial fibrillation was present. In those patients with high risk, adding partial Glenn anastomosis reduced the operative mortality from 24% to 6%. Another benefit of the cavo-bipulmonary anastomosis was better functional tolerance of mild residual tricuspid valve incompetence. Those patients with the tricuspid sack arrangement had a high rate of reoperation (2/11) and valve replacement (3/11), but suffered no operative deaths. We conclude that tricuspid valvoplasty associated with longitudinal right ventricular plication is superior to valve replacement. The arrangement producing a tricuspid sack is not suitable for conservative surgery. An associated cavo-pulmonary anastomosis decreases the operative mortality in patients at high risk, and seems to preserve right ventricular function.

Actuarial Analysis↗
PubMed2005

Prediction of circulatory equilibrium in response to changes in stressed blood volume.

Accurate prediction of cardiac output (CO), left atrial pressure (PLA), and right atrial pressure (PRA) is a prerequisite for management of patients with compromised hemodynamics. In our previous study (Uemura et al. Am J Physiol Heart Circ Physiol 286: H2376-H2385, 2004), we demonstrated a circulatory equilibrium framework, which permits the prediction of CO, PLA, and PRA once the venous return surface and integrated CO curve are known. Inasmuch as we also showed that the surface can be estimated from single-point CO, PLA, and PRA measurements, we hypothesized that a similar single-point estimation of the CO curve would enable us to predict hemodynamics. In seven dogs, we measured the PLA-CO and PRA-CO relations and derived a standardized CO curve using the logarithmic function CO = SL[ln(PLA - 2.03) + 0.80] for the left heart and CO = SR[ln(PRA - 2.13) + 1.90] for the right heart, where SL and SR represent the preload sensitivity of CO, i.e., pumping ability, of the left and right heart, respectively. To estimate the integrated CO curve in each animal, we calculated SL and SR from single-point CO, PLA, and PRA measurements. Estimated and measured CO agreed reasonably well. In another eight dogs, we altered stressed blood volume (-8 to +8 ml/kg of reference volume) under normal and heart failure conditions and predicted the hemodynamics by intersecting the surface and the CO curve thus estimated. We could predict CO [y = 0.93x + 6.5, r2 = 0.96, standard error of estimate (SEE) = 7.5 ml.min(-1).kg(-1)], PLA (y = 0.90x + 0.5, r2= 0.93, SEE = 1.4 mmHg), and PRA (y = 0.87x + 0.4, r2= 0.91, SEE = 0.4 mmHg) reasonably well. In conclusion, single-point estimation of the integrated CO curve enables accurate prediction of hemodynamics in response to extensive changes in stressed blood volume.

Animals↗
PubMed1998

The effects of ventricular pacing on left ventricular geometry, function, myocardial oxygen consumption, and efficiency of contraction in conscious dogs.

The effects of ventricular pacing on left ventricular (LV) dynamic geometry, function, and myocardial oxygen consumption (MVO2) were measured in 12 conscious dogs using sonomicrometry, micromanometry, ultrasonic flow probes, and oximetry catheters during right atrial (A-) and right ventricular (V-) pacing at 150 beats/min. Systolic function was quantified using slopes (MW) and volume-intercepts (VW) of linear relationships between end-diastolic volume (EDV) and stroke work (SW) for data obtained during vena caval occlusion. V-pacing shifted SW-EDV relationships downward (MW decreased from 97 +/- 21 to 81 +/- 21 Kerg/mL) and to the right (VW increased from 14 +/- 11 to 20 +/- 12 mL) in comparison with A-pacing (P < 0.02). These functional changes correlated with altered contractile geometry manifest as early shortening in the septal free wall relative to anterior-posterior dimension (increased minor axis mid-wall eccentricity at end-diastole and begin-ejection). Steady-state LV power output decreased from 802 +/- 213 mW during A-pacing to 514 +/- 170 mW during V-pacing (P < 0.05), while MVO2 remained relatively unchanged during V-pacing (10 +/- 3 mL O2/min vs 11 +/- 3 mL O2/min during A-pacing, P = NS). As a result, overall LV efficiency decreased from 0.24 +/- 0.08 during A-pacing to 0.16 +/- 0.06 during V-pacing (P < 0.05). These data illustrate the impact of V-pacing on dynamic LV geometry and function, including impaired LV work output at all physiological levels of preload. Most importantly, the relationship between LV work output and MVO2 is depressed during V-pacing, emphasizing the interaction between LV mechanics and pump efficiency in intact subjects. As a result, measures taken to restore normal contractile geometry might improve LV efficiency and performance when V-pacing is necessary.

Animals↗
PubMed1986

Management of pulmonary atresia with intact ventricular septum.

Infants with pulmonary atresia and intact ventricular septum pose a difficult clinical problem. Pulmonary valvotomy has been widely recommended for relief of the right ventricular obstruction, and most infants also have had an aortopulmonary shunt placed to ensure pulmonary blood flow. We have evolved a different approach that includes placement of a right ventricular outflow tract patch initially and continuation of prostaglandin E1 infusion postoperatively until the need for a shunt can be determined. We report here our management of 15 neonates with this diagnosis and suprasystemic right ventricular pressures. All of the infants were placed on a regimen of prostaglandin E1 before the operation to improve pulmonary blood flow, and all had an outflow patch placed early in life. Satisfactory postoperative right ventricular function, which would allow both outflow patching and ductus ligation, could be confidently predicted in only two of the 15 patients. For nine of the 15 an outflow patch was placed and prostaglandin was infused postoperatively to provide pulmonary blood flow until right ventricular function became adequate. Early in the series, three other infants were judged to need an aortopulmonary shunt in addition to decompression by an outflow patch, and one infant had only a shunt placed. Postoperatively, adequate pulmonary blood flow was present in all, and 11 of the 15 (73%) survived. Three of the deaths (average 2.8 days) after the outflow patch operation probably resulted from premature cessation of the prostaglandin infusion. One neonate with an outflow patch and a shunt died of myocardial ischemia because of coronary artery steal through right ventricular sinusoids. One late death occurred suddenly in the child with only a shunt, presumably because of an arrhythmia. The remaining survivors (10/15, 67%) are alive and have had complete repair. Study of these patients has also revealed that the definition of adequate right ventricular size needs to be more liberal. Five of the 10 surviving patients had a residual atrial septal defect with a right-to-left shunt at the ages of 1 to 3 years, but balloon occlusion of the atrial septal defect during cardiac catheterization revealed that the right ventricle in these patients was functionally adequate. These five children subsequently underwent closure of the atrial septal defect, and in two the aortopulmonary shunt was also taken down. In summary, correction was achieved in all survivors, in contrast to reported studies in which many patients are living with shunts.(ABSTRACT TRUNCATED AT 400 WORDS)

Angiography↗
PubMed2002

The effect of amlodipine on exercise-induced pulmonary hypertension and right heart function in patients with chronic obstructive pulmonary disease.

The aim of the study was to investigate the pulmonary vasodilator effect of the dihydropyridine calcium channel blocker amlodipine in patients with clinically stable chronic obstructive pulmonary disease (COPD) and pulmonary hypertension (PH). Many patients with COPD develop chronic PH and this may predict mortality in this disorder. The treatment with calcium channel blockers is accepted as a therapeutic strategy for primary pulmonary hypertension. In twenty male patients (mean age 57+/-7 years) with clinically stable COPD and PH, we investigated whether amlodipine could effectively decrease pulmonary vascular resistance (PVR) and pulmonary arterial pressure (PAP) and improve right heart function. PAP was recorded by a balloon-tipped thermodilution catheter and cardiac output was determined in triplicate by thermodilution at rest and during exercise. In addition, blood gas values were determined from the capillary blood of the earlobe. All measurements were done under identical conditions before and after 18 days of chronic treatment: with 10 mg amlodipine once daily starting with 5mg in the first week. At a mean maximal achieved workload of 71.3+/-20 Watts, amlodipine achieved a significant reduction in PVR (-13.4%; p<0.01) and PAP (-12.1%; p<0.001) implying an improved right heart function assessed by a significant reduction in mean right atrial pressure (-20.6%; p<0.05). During the action of amlodipine there were no significant changes in pulmonary gas exchange and pulmonary capillary wedge pressure. Amlodipine given as a single daily oral dose of 10mg is a safe and effective pulmonary vasodilator in COPD patients with PH and leads to an improvement in right heart function.

Amlodipine↗
PubMed1991

Subclavian vein-to-right atrial bypass for symptomatic venous hypertension.

A new surgical technique for bypassing subclavian vein thromboses in patients undergoing hemodialysis is presented. Subclavian vein stenosis or occlusion can occur after the use of temporary access catheters in subclavian vein dialysis. If this occurs in a patient with an arteriovenous access fistula of an ipsilateral upper extremity, venous hypertension, massive edema of the arm, and dysfunction of the access graft may result. In 2 patients with this condition, we successfully performed axillary vein-to-right atrial bypass, which resolved swelling and restored function of the access graft. This may be an appropriate surgical option for symptomatic venous hypertension in such patients.

Anastomosis, Surgical↗
PubMed1992

Outcome in neonates with Ebstein's anomaly.

The presentation and outcome of 50 patients with neonatal Ebstein's anomaly seen from 1961 to 1990 were reviewed. The majority (88%) presented in the 1st 3 days of life; cyanosis (80%) was the most common presenting feature. Associated defects, present in 27 infants (54%), included pulmonary stenosis in 11 and atresia in 7. Nine patients (18%) died in the neonatal period; there were 15 late deaths (due to hemodynamic deterioration in 9, sudden death in 5 and a noncardiac cause in 1) at a mean age of 4.5 years (range 4 months to 19 years). Actuarial survival at 10 years was 61%. A new echocardiographic grade (1 to 4 in order of increasing severity of the defect) was devised with use of the ratio of the area of the right atrium and atrialized right ventricle to the area of the functional right ventricle and left heart chambers. Cardiac death occurred in 0 of 4 infants with grade 1, 1 (10%) of 10 with grade 2, 4 (44%) of 9 with grade 3 and 5 (100%) of 5 with grade 4. In a multivariate analysis of clinical and investigational features at presentation, echocardiographic grade of severity was the best independent predictor of death. Neonates with Ebstein's anomaly have a high early mortality rate and those surviving the 1st month of life remain at high risk of late hemodynamic deterioration or sudden death. Echocardiographic grading of severity of the defect permits prognostic stratification.

Abnormalities, Multiple↗
PubMed2005

Management of a large organized intraatrial catheter-tip thrombus in a child with acquired immunodeficiency syndrome using escalating tissue plasminogen activator infusions.

OBJECTIVES: To describe the dissolution of a large organized intraatrial catheter-tip thrombus using a novel aggressive dose escalation of tissue plasminogen activator infusion. DESIGN: Case report. SETTING: A six-bed pediatric intensive care unit (ICU) at a university hospital. PATIENT: An 8-yr-old with acquired immunodeficiency syndrome with a large organized intraatrial thrombus at the tip of an indwelling central venous catheter placed for total parenteral nutrition 2 months before presentation. INTERVENTION: Escalating dose of tissue plasminogen activator infusion. MEASUREMENTS: A large intraatrial catheter-tip thrombus (2.5 x 3 cm) was an incidental finding on an echocardiogram done to assess cardiac function. The thrombus occupied almost half the right atrial cavity and hit the tricuspid valve with each heartbeat without obstruction of tricuspid inflow. The catheter had no blood return from either lumen for >1 month. Protein C, protein S, and antithrombin III were normal, and factor V Leiden and prothrombin gene mutations were absent. Blood cultures were negative. Pediatric and cardiovascular surgeons recommended open-heart surgery as the safest option for catheter removal to avoid the risk of superior vena cava occlusion, vascular rupture, or embolization. A second opinion concurred. A trial of thrombolytic therapy with tissue plasminogen activator infusions was started at 0.1 mg/kg/hr for 6 hrs daily. No change in thrombus size was seen on a followup echocardiogram after 4 days. An aggressive dose escalation (0.15, 0.2, 0.25 mg/kg/hr for 6 hrs) was done over the next 5 days in an attempt to avoid open-heart surgery. Risks regarding disseminated intravascular coagulation and bleeding were presented to the parents. MAIN RESULTS: Followup echocardiogram on day 10 showed complete resolution of the thrombus. No changes in respiratory/hemodynamic status or oxygen saturation were observed. Studies for disseminated intravascular coagulation remained stable, and no clinical bleeding was seen. The catheter was safely removed surgically; pathology examination showed no residual thrombus. CONCLUSIONS: Prolonged infusion of tissue plasminogen activator in escalating doses was safe and effective in the management of a large intracardiac catheter-tip thrombus and helped avoid open-heart surgery. In view of the potential hazards of tissue plasminogen activator, close pediatric ICU monitoring is indicated with the use of high-dose tissue plasminogen activator infusions.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Characterization of responses to cromakalim and pinacidil in smooth and cardiac muscle by use of selective antagonists.

1. In dog isolated coronary artery (precontracted with endothelin, 10 nM) cromakalim (0.1-30 microM) and pinacidil (1-30 microM) produced concentration-dependent vasorelaxant responses. The effects of these compounds could be blocked by glibenclamide (3 microM), phentolamine (30 microM) or alinidine (30 microM) to a similar extent, indicating that both agents alter vascular tone through the same mechanism in this preparation. 2. The ability of the antagonists glibenclamide, phentolamine and alinidine to block the response to cromakalim in a number of smooth muscle types from the guniea-pig was determined. Cromakalim (0.1-30 microM) produced concentration-dependent relaxant responses in thoracic aorta (precontracted with endothelin, 30 nM), ileum (precontracted with K+, 25 mM) and trachea (spontaneously contracted). Responses to cromakalim in all tissues could be blocked by the three antagonists. However, significantly higher concentrations of the antagonists were required to block responses in the thoracic aorta than in the ileum or trachea. Given that the rank order of potency of the antagonists was similar in all tissues (i.e. glibenclamide greater than phentolamine = alinidine), this result may suggest vascular K+ channels opened by cromakalim are quantitatively but not qualitatively different in vascular compared with non-vascular smooth muscle. Glibenclamide was approximately 10 times more potent than phentolamine or alinidine. 3. Cromakalim had minimal functional effects on the rat spontaneously beating right atrial (rate) or electrically driven left ventricular strip (force) preparations. Similarly the three antagonists studied failed to alter force generation in the right ventricular strip. However alinidine and phentolamine did produce a dose-related bradycardia in the spontaneously beating right atria. This effect appears to be unrelated to blockade of the K+ channel opened by cromakalim since glibenclamide, the most potent K+ channel antagonist studied, failed to produce the same response. 4. It would appear that the K+ channel opened by cromakalim is present in a number of vascular and non-vascular smooth muscle. Based on the potency of the three antagonists studied, there appears to be little heterogeneity in the process activated by cromakalim in vascular and non-vascular smooth muscle.

Animals↗
PubMed1986

Dipyridamole-induced coronary vasodilation in human transplanted heart: preliminary report.

Coronary sinus blood flow and resistance were studied before and after intravenous dipyridamole in 4 patients with transplanted heart and normal coronary arteriogram treated by cyclosporine-prednisolone. Results were compared to those of a normal group of 7 subjects. Left ventricular endomyocardial biopsies were performed in the heart transplanted group. Mean right atrial pressure, cardiac index and left ventricular function were normal in the transplanted heart group. Mean aortic pressure and systemic vascular resistances were significantly higher in the transplanted group than in normals (p less than 0.01), but coronary resistance were similar. Dipyridamole-induced vasodilation resulted in an increased coronary sinus blood flow and a decreased coronary resistance in both groups, but these effects were reduced in 1 patient with a transplanted heart that evidenced an important perivascular fibrosis after a subacute rejection. In conclusion, this preliminary report of coronary blood flow in patients with transplanted heart indicates that the ability of coronary sinus blood flow to increase after dipyridamole is normal in the transplanted heart without allograft rejection. A major limitation in coronary vasodilation was observed in 1 patient with rejection antecedents and perivascular fibrosis, which could play a role in left ventricular function deterioration in some patients after heart transplantation.

Adult↗
PubMed2002

Impact of telemedicine on the practice of pediatric cardiology in community hospitals.

BACKGROUND: Tele-echocardiography has the potential to bring real-time diagnoses to neonatal facilities without in-house pediatric cardiologists. Many neonates in rural areas, smaller cities, and community hospitals do not have immediate access to pediatric sonographers or echocardiogram interpretation by pediatric cardiologists. This can result in suboptimal echocardiogram quality, delay in initiation of medical intervention, unnecessary patient transport, and increased medical expenditures. Telemedicine has been used with increased frequency to improve efficiency of pediatric cardiology care in hospitals that are not served by pediatric cardiologists. Initial reports suggest that telecardiology is accurate, improves patient care, is cost-effective, enhances echocardiogram quality, and prevents unnecessary transports of neonates in locations that are not served by pediatric cardiologists. OBJECTIVE: We report the largest series to evaluate the impact of telemedicine on delivery of pediatric cardiac care in community hospitals. We hypothesized that live telemedicine guidance and interpretation of neonatal echocardiograms from community hospitals is accurate, improves patient care, enhances sonographer proficiency, allows for more efficient physician time management, increases patient referrals, and does not result in increased utilization of echocardiography. METHODS: Using desktop videoconferencing computers, pediatric cardiologists guided and interpreted pediatric echocardiograms from 2 community hospital nurseries 15 miles from a tertiary care center. Studies were transmitted in real-time using the H.320 videoconferencing protocol over 3 integrated services digital network lines (384 kilobits per second). This resulted in a frame rate of 23 to 30 frames per second. Sonographers who primarily scanned adult patients but had received additional training in echocardiography of infants performed the echocardiograms. Additional views were suggested as deemed necessary by the interpreting physician, and interpretations were made during the videoconference. The results of the echocardiogram and recommendations for patient care were communicated to the referring physician over the telemedicine system. Analyses of accuracy, patient treatment, echocardiogram quality, time to diagnosis, pediatric cardiologist practice time management, patient referral patterns, and echocardiography utilization were conducted prospectively. RESULTS: A total of 500 studies in 364 patients were transmitted during a 30-month period. The most common indication for echocardiography was to rule out congenital heart disease (208 of 500 studies). Signs and symptoms that prompted this concern included cyanosis, murmur, tachypnea, genetic syndrome, arrhythmia, abnormal fetal echocardiogram, and maternal diabetes. Other indications included suspected patent ductus arteriosus (PDA; 182 of 500 studies), intracardiac clot or catheter position, persistent pulmonary hypertension, and hemodynamic instability. Cardiac diagnoses included complex congenital heart disease (n = 16), noncritical heart disease (n = 107), and PDA (n = 86). Additional diagnoses included persistent pulmonary hypertension (n = 12), septal hypertrophy (n = 18), right atrial mass/clot/vegetation (n = 11), and decreased cardiac function (n = 6). An umbilical venous catheter was visualized in the left atrium in 9% (45 of 500) of all studies. No significant abnormalities were found in 244 studies. Major diagnoses were confirmed by subsequent review of videotape in all studies. Comparison of final videotape interpretation to initial telemedicine diagnosis resulted in 1 minor diagnostic change (membranous versus inlet ventricular septal defect). Echocardiograms were performed in subsequent visits in 264 patients. The diagnosis was altered in 3 patients. Telemedicine had an immediate impact on patient care in 151 transmissions. The most common interventions were indomethacin treatment for PDA (n = 76), retraction of umbilical venous catheters from the left atrium (n = 45), inotropic or anticongestive therapy (n = 19), anticoagulation (n = 8), and prostaglandin infusion (n = 8). Nineteen patients were transported to our hospital because of the telemedicine diagnosis. Inpatient or outpatient cardiology follow-up was recommended in an additional 131 studies and did not result in any change in the initial management. The most common diagnoses in these patients were ventricular septal defect (n = 56), atrial septal defect (n = 21), septal hypertrophy (n = 9), intracardiac thrombosis (n = 8), and pulmonary valve stenosis (n = 4). We speculate that the immediate availability of an echocardiographic diagnosis likely prevented unnecessary transport in 14 cases. Recommendations for additional views or adjustment of echocardiography machine settings were made in 95% of transmissions. Real-time guidance was especially helpful in suprasternal notch and subcostal sagittal imaging. Depth, color Doppler sector size, and color Doppler scale were frequently adjusted from routine adult settings during the teleconference. The average time from request for echocardiogram to completion of the videoconference was 28 +/- 14 minutes. This was significantly shorter than the waiting time (12 +/- 16 hours) for the videotape to be delivered by courier. Telemedicine eliminated the need for consultation in 194 cases and allowed the cardiologist to delay the visit until the end of the day in an additional 26 cases. This resulted in average time savings of 4.2 person-hours/wk based on travel and consultation time. Utilization of echocardiography was similar before (35 of 1000 births) and after (33 of 1000 to 43 of 1000) telemedicine installation. The percentage of neonatal echocardiograms that were interpreted by our practice increased from 63% to 81% at 1 hospital and from 0% to 100% at the other hospital. CONCLUSION: Real-time transmission of neonatal echocardiograms from community hospitals over 3 integrated services digital network lines is accurate and has the potential to improve patient care, enhance echocardiogram quality, aid sonographer education, and have a positive impact on referral patterns and time management without increasing the utilization of echocardiography.

Cardiology Service, Hospital↗
PubMed2001

[A case of tuberculous pericarditis developing constrictive pericarditis].

A case of constrictive pericarditis which developed after the onset of clinical manifestation of tuberculous pericarditis was reported. A 75-year-old male, complaining of anorexia, was admitted to our hospital. Adenosinedeaminase (ADA) level in pericardial effusion was found to be increased, and the culture of pericardial effusion was positive for tubercle bacilli. Diagnosed as having tuberculous pleuritis and pericarditis, he underwent chemotherapy for tuberculosis. However, massive pleural effusion developed later and pleural effusion drainage was carried out. Despite repeated drainage, pleural effusion continued to recur. Chest CT revealed apparent pericardial thickening, in addition, cardiac catheterization revealed elevation of mean right atrial pressure and marked deterioration of cardiac functions including decrease of cardiac output. These findings were compatible with constrictive pericarditis. After these investigations a diagnosis of constrictive pericarditis was established, and the patient underwent a pericardiectomy. Pathological examination of resected specimens revealed tuberculous inflammation.

Aged↗