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PubMed1988

Late pericardial tamponade after aortic and mitral valve replacement.

A report is presented on a patient who developed a pericardial tamponade on the 11th postoperative day after double valve replacement. Instead of classical signs of tamponade, however, the signs of posterior wall infarction were most prominent. The administration of nitrate resulted in deterioration of the circulatory situation, but the ST elevation in supraventricular tachycardia occurring from time to time regressed. As before the operation, coronary angiography showed normal conditions, and valve function was normal. The contrast-medium imaging of the right ventricle suggested a compression from ventral, and the right ventricular and right atrial pressures corresponded to a tamponade situation: in rethoracotomy, a blood coagulum roughly the size of a fist was found ventral to the right ventricle. After clearing the hematoma, there was an immediate improvement of the circulatory situation, and the ECG alterations regressed. Enzyme alterations in terms of myocardial infarction did not occur. We explained the symptoms as follows: The coagulum compressed the outflow tract of the right ventricle and thus caused on the one hand the hemodynamic situation of tamponade and on the other hand an extreme vagotonia with consecutive bradycardia and ST elevation.

Aortic Valve↗
PubMed1983

Central body temperature as a guide to optimal heart rate.

Studies in man suggest that fixed-rate artificial pacemakers do not return hemodynamic function to normal, since the principal mechanism for the increase in cardiac output with exercise, increased heart rate, is not restored. Special pacemakers are available that can detect atrial activity and pace the ventricles in coordination, but nearly half of the patients receiving artificial pacemakers have abnormal atrial function (atrial fibrillation, sick sinus syndrome). This study examined the effects of exercise on the temperature of blood returning to the right atrium. Precision thermistors, placed in the right hearts of conscious dogs, recorded temperature increases of 1 degree C (range 0.4-1.5 degrees C) during submaximal treadmill exercise. Temperature change correlated well with work load and changes in heart rate.

Animals↗
PubMed1996

Radiofrequency catheter ablation of an incessant supraventricular tachycardia initiated by a Hisian parasystole.

The coexistence of a parasystolic focus, tachycardia dependent right bundle branch aberrancy, and an AV accessory pathway is reported here. This condition was present in a 40-year-old man, which led to an incessant AV reciprocating tachycardia. Further electrophysiological study revealed that the parasystolic focus was located somewhere in the His bundle; endocardial mapping disclosed a right posterior accessory pathway. Radiofrequency current was delivered at the atrial level of the right posterolateral AV groove and successfully ablated the accessory pathway, leading to a dramatic improvement in cardiac function. In conclusion, the recognition of the electrophysiological mechanism of incessant supraventricular tachycardia was of crucial importance for the therapy decision. A definitive intervention using radiofrequency catheter ablation should be considered early and not postponed in patients with tachycardia-induced cardiomyopathy.

Adult↗
PubMed1976

Persistent right atrial standstill.

An asymptomatic patient with cardiomegaly caused by isolated right atrial standstill is reported. The right atrium showed no evidence of contraction on pressure records or angiographically, while the left atrium functioned normally.

Adult↗
PubMed1993

Angiotensin I and II exert inotropic effects in atrial but not in ventricular human myocardium. An in vitro study under physiological experimental conditions.

BACKGROUND: The renin-angiotensin system with its renal-humoral and local myocardial components plays an important role in the development and progression of chronic heart failure. Whereas angiotensin receptors have been found in atrial and ventricular myocardium of different species including humans, its influence on myocardial contractility is not yet defined in human failing myocardium and especially in human nonfailing myocardium. METHODS AND RESULTS: We measured force development of right atrial and right and left ventricular myocardial preparations of patients with a variety of cardiac diseases. To evaluate the physiological effects of angiotensin, experimental temperature and stimulation rates were 37 degrees C and 60 beats per minute, respectively. Angiotensin I and II increased peak developed force in atrial myocardial preparations obtained from patients without heart failure in a concentration-dependent manner. At optimal concentrations, peak developed force is increased from 10.2 +/- 1.8 to 12.3 +/- 1.9 mN/mm2 by angiotensin I (P < .05) and from 15.4 +/- 2.1 to 20.5 +/- 3.3 mN/mm2 by angiotensin II (P < .05). This effect was not influenced by pretreatment with propranolol (10(-6) mol/L) and prazosin (10(-5) mol/L) but was completely blocked by saralasin (10(-6) mol/L). The positive inotropic effect of angiotensin I could be blocked by enalaprilate (10(-5) mol/L). Neither angiotensin I nor angiotensin II had any effect in preparations of the left ventricle from patients with idiopathic dilated cardiomyopathy, mitral valve stenosis, and incompetence or in patients with no significant heart disease. Additionally, no effect could be seen when angiotensin II was applied to right ventricular preparations from infants undergoing reconstructive heart surgery for tetralogy of Fallot. CONCLUSIONS: Angiotensin I and II exert positive inotropic effects via angiotensin receptors in atrial preparations but not in right or left ventricular preparations. Furthermore, the existence of a local myocardial angiotensin converting enzyme with functional importance is shown.

Aged↗
PubMedDate not supplied

A prospective study of complications in Hickman right-atrial catheters in marrow transplant patients.

One hundred forty-three large bore right-atrial catheters (RACs) in 111 bone marrow transplant recipients were prospectively analyzed for the incidence of complications interfering with catheter function. Of the 143 RACs, 108 (76%) were patent on departure from Seattle or death. Infectious complications occurred in 63 (44%) of the catheters, resulting in 18 (13%) removals. Noninfectious complications occurred with 54 (38%) of the catheters, resulting in 17 (12%) removals. Successful interventions included catheter repair, dissolving precipitates with ammonium chloride solution, and declotting catheter lumens with heparin and/or urokinase. We conclude that RACs continue to be reliable and safe devices to use in marrow transplant patients. Complications interfering with catheter function are frequent; however, most can be resolved without the need to remove the catheter.

Adolescent↗
PubMed2002

Aspergillus infection in a large thrombus of a permanent ventricular pacing lead.

Pacemaker lead infection is a rare but a dangerous complication. Diagnosis can usually be established by the clinical picture and blood cultures. Transesophageal two dimensional echocardiography might be crucial in the diagnosis by visualizing pacing lead vegetations. Medical treatment alone is rarely successful, and several studies have suggested the infected pacemaker systems should be removed quickly for optimal management. We describe a case of Aspergillus infection in a permanent ventricular pacing lead, which appears to be the first reported case in Korea. A 30-yr-old man was evaluated for the symptoms and signs of congestive heart failure 3 yr after DDD pacemaker implantation. The transthoracic and transesophageal echocardiogram showed a large movable round shaggy mass attached to a ventricular lead in the right atrium. The atrial and ventricular leads were removed during cardiopulmonary bypass, and a new epicardial pacing system was implanted. The functional ventricular pacemaker lead was encased in a large organized thrombus. Histological findings were consistent with Aspergillus infection in a large thrombus attached to a pacemaker lead.

Adult↗
PubMed1984

[Determination of the size of the right atrium using two-dimensional echocardiography].

Echocardiographical and functional parameters of the right ventricle have been established. In addition, to improve the analysis of right heart dynamics, normal values for right atrial dimensions and the tricuspid valve anulus diameter are required. We therefore examined 30 normal adult subjects, 15 males (aged 31 +/- 10 years, mean +/- SD) and 15 females (aged 28 +/- 8 years) using two-dimensional echocardiography in the apical 4-chamber view. The contour of the right atrium was delineated with a light pen, and the end-diastolic and end-systolic areas were calculated using a computerized integration method; the percentage area shortening fraction was determined as end-systolic area - end-diastolic area/end-systolic area. The diameter of the tricuspid anulus was measured in the ECG-triggered two-dimensional stop frame; the greatest diameter was reached immediately after the end of the P-wave in the ECG and the smallest diameter at midsystole. Thus it was possible to calculate the anulus shortening fraction as greatest diameter - shortest diameter/greatest diameter. For determination of the circumference of the tricuspid valve anulus a circular geometry was assumed. The mean values, the standard deviation and the 95% upper confidence bound for the 90th percentile were calculated. The end-diastolic right atrial area in the apical 4-chamber view was 3.0 +/- 0.8 cm2/m2 in the whole study group (males 3.4 +/- 1.8 cm2/m2 and females 2.6 +/- 0.5 cm2/m2) and the end-systolic area was 6.9 +/- 1.0 cm2/m2 (males 7.1 +/- 1.1 cm2/m2 and females 6.6 +/- 0.9 cm2/m2); the calculated value of the area shortening fraction was 56.7 +/- 9.7%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

Dual lumen catheters for angioaccess in patients with leukemia.

Dual lumen long-term indwelling right atrial catheters have been used to improve venous access in adult patients with leukemia. Twenty-eight such catheters have functioned for 1,895 days in 28 patients over the past eight months at the University of Maryland Hospital. Although insertion of the dual lumen catheter was more technically demanding than insertion of a single lumen catheter, the greater versatility in drug management (e.g., administration of two continuous infusions simultaneously or one continuous infusion leaving one line for platelets, blood, antibiotics or venous sampling) provided by the extra venous portal of entry more than compensated for any increased operative time (average, 58 vs 39 min/insertion). Eight episodes of bacteremia (0.37/100 patient days) occurred in these patients, but only one of these was associated with an exit site infection: the remainder were secondary to infections remote from the catheter. No catheter was removed as a result of these episodes, nor was any removed for ante mortem mechanical failure. The dual lumen catheter is a safe reliable device for providing angioaccess in patients with leukemia and offers substantially greater flexibility than the single lumen catheter.

Adult↗
PubMed1980

Echocardiographic studies of children operated on for congenital heart disease; evaluation during the first postoperative year.

Fifty-five children in 6 diagnostic groups were followed with repeated echocardiographic examinations during the first postoperative year to establish profiles for different congenital cardiac malformations. One year after total correction, patients with Fallot's anomaly, with and without previous shunt, showed an enlargement of the right ventricular dimension (RVD), the left ventricular internal dimension (LVIDd), the aortic root dimension (AOD), and the left atrial dimension (LAD) compared with normal. In patients with ventricular septal defect (VSD), LVIDd was enlarged; in patients who had been operated on previously with pulmonary banding, both RVD and AOD were enlarged. Patients with VSD and pulmonary stenosis (PS) showed enlarged RVD and AOD but small right ventricular outflow tract (RVOT). Patients with secundum atrial septal defect (ASD) had enlarged RVD, AOD, LVIDd, and LAD. Left ventricular function as judged by echocardiography was normal in all groups pre- and postoperatively. The importance of establishing postoperative echocardiographic profiles is illustrated by patients where deviations from expected findings indicated an unsatisfactory result of the operation and the need for reoperation.

Adolescent↗
PubMed1990

The pericardium exerts constraint on the right ventricle during cardiac surgery.

The right ventricle may be particularly susceptible to the effects of pericardial constraint. This study examined the effects of pericardiotomy on right ventricular function. Twenty-four anesthetized patients with coronary artery disease, but without evidence of pericardial pathology, were studied. Anesthesia consisted of fentanyl (100 micrograms.kg-1), diazepam, pancuronium, and 100% oxygen. The American Edwards REF-1 Cardiac Output Computer, rapid-response thermistor pulmonary arterial catheter, and a radial arterial catheter were used to measure hemodynamic variables. Baseline measurements were obtained with the sternum fully retracted. The measurements were then repeated following pericardiotomy by a midline incision. There were significant (P less than 0.05) changes in systolic arterial pressure (+4.5%), mean arterial pressure (+3.7%), systolic pulmonary arterial pressure (+11.8%), cardiac output (+9.1%), stroke volume (+6.9%), right ventricular end-diastolic volume (+7.6%), and right atrial pressure (-8.6%). In the current study, pericardiotomy augmented right ventricular diastolic filling and stroke volume, while the right atrial pressure decreased. These results support the concept of pericardial constraint.

Adult↗
PubMed2000

[Effect of radiofrequency catheter ablation on autonomic tone in patients with common atrial flutter: difference depending on the site of ablation].

OBJECTIVES: Radiofrequency catheter ablation (RFCA) of the inferior vena cava-tricuspid annulus isthmus has become an effective procedure for radical treatment of common atrial flutter. This site is close to the right atrial posteroseptal region, so vagal denervation after slow pathway ablation in patients with atrioventricular nodal reentrant tachycardia can also occur after the procedure. To confirm this hypothesis, we tested whether autonomic disturbance can occur after RFCA in 16 patients with common atrial flutter. METHODS: Parameters of the autonomic function were measured using several components of the time domain analyses and power spectra of heart rate variability calculated from Holter recordings and the baroreflex sensitivity. Patients were divided into 2 groups based on the location of the ablated area: the isthmus group (9 patients) with the ablated area of the exact isthmus, and the posteroseptal group (7 patients) with the ablated area slightly shifted toward the right atrial posteroseptal position. All values after RFCA were compared with those before RFCA, and the ratio (after/before) was compared between the groups. The correlation between the ratio and cumulative delivered energy was also studied for each parameter. RESULTS: After RFCA, the heart rate increased, and the SD, rMSSD and pNN50 decreased significantly in the posteroseptal group, whereas no significant changes occurred in the isthmus group. The high frequency of the power spectra decreased after RFCA only in the posteroseptal group, and the ratio was significantly smaller in the posteroseptal group compared to the isthmus group. A significant reverse correlation between the ratio of the high frequency and cumulative energy was observed only in the posteroseptal group. The baroreflex sensitivity tended to be diminished after RFCA only in the posteroseptal group. CONCLUSIONS: Vagal denervation can occur after RFCA of common atrial flutter when the ablation site is shifted toward the right atrial posteroseptal region.

Atrial Flutter↗
PubMed2003

Comparison of permanent left ventricular and biventricular pacing in patients with heart failure and chronic atrial fibrillation: a prospective hemodynamic study.

BACKGROUND: Left ventricular pacing (LVP) and biventricular pacing (BVP) have been proposed as treatments for patients with advanced heart failure complicated by discoordinate contraction due to intraventricular conduction delay. For patients in sinus rhythm, BVP works in part by modulating the electronic atrial-ventricular time delay and thus optimizing contractile synchrony, the contribution of atrial systole, and reducing mitral regurgitation. However, little is known of the mechanisms of BVP in heart failure patients with drug-resistant chronic atrial fibrillation. HYPOTHESIS AND METHODS: LVP differs from BVP because hemodynamic and clinical improvement occurs in association with prolongation rather than shortening of the QRS duration. We sought to determine if LVP or BVP improves mechanical synchronization in the presence of atrial fibrillation. Thirteen patients with chronic atrial fibrillation, severe heart failure and QRS >or=140 ms received (after His bundle ablation) a pacemaker providing both LVP and BVP. The mean age was 62 +/- 6 years and left ventricular ejection fraction was 24 +/- 8%. After a baseline phase of one month with right ventricular pacing, all patients underwent in random order 2 phases of 2 months (LVP and BVP). At the end of each phase, an echocardiogram, a hemodynamic analysis at rest and during a 6-minute walking test and a cardio-pulmonary exercise test were performed. RESULTS: LVP and BVP provided similar performances at rest (p = ns). The 6-minute walking test revealed similar performances in both pacing modes but patients were significantly more symptomatic at the end of the test with LVP ( p = 0.035). The cardio-pulmonary exercise test showed higher performances with BVP (92 +/- 34 Watts) vs. LVP (77 +/- 23; p = 0.03). LVP was associated with significantly more premature ventricular complexes recorded during the 6 minute walking test (49 +/- 71) than BVP (10 +/- 23; p = 0.04). CONCLUSIONS: In this small series of patients with atrial fibrillation, congestive heart failure and a prolonged QRS duration, LVP and BVP provided similar hemodynamic effects at rest whereas BVP was associated with better hemodynamic effects during exercise and fewer premature ventricular complexes. Although the mechanisms for the observed differences are uncertain, it is possible that there is worsening of right ventricular function due to a rise in left-to-right electromechanical delay during exercise. Increased catecholamines release might contribute to the lower exercise tolerance and greater number of premature ventricular complexes recorded during exercise observed during LVP compared to BVP. RECOMMENDATIONS: Patients with atrial fibrillation, heart failure and QRS prolongation who are candidates for His-bundle ablation and cardiac resynchronization therapy may respond better to BVP rather than to LVP.

Atrial Fibrillation↗
PubMedDate not supplied

Capacity of intrinsic cardiac neurons to modify the acutely autotransplanted mammalian heart.

The capacity of the intrinsic cardiac nervous system to modify the acutely autotransplanted heart was investigated in eight anesthetized open-chest canine preparations in which the adrenal glands had been removed from the circulation. Cardiac effects elicited by isoproterenol and nicotine were also examined before and after heart-lung transplantation. Cardiac augmentation induced by isoproterenol was similar before and immediately after cardiopulmonary transplantation, indicating that the surgery did not obtund cardiac myocyte function significantly. The initial bradycardia induced by nicotine was greater before transplantation. The subsequent augmentation in left atrial systolic pressure, as well as right and left ventricular intramyocardial systolic pressures, induced by nicotine were similar before and after transplantation. When nicotine was administered to transplanted preparations after atropine administration, cardiac augmentation was induced. Cardiac augmentation was not induced by nicotine after subsequent beta-adrenergic blockade. These data indicate that nicotine-sensitive adrenergic neurons which accompany the transplanted heart are capable of inducing considerable cardiac augmentation. Power spectral analysis of heart rate and left ventricular chamber rate of pressure rise variability indicated an almost complete lack of power in these indexes after, as opposed to before, transplantation. Together with intrinsic cardiac cholinergic neurons, intrinsic cardiac adrenergic neurons may be responsible for physiologically and pharmacologically induced alterations in cardiac variables that occur in acutely transplanted hearts.

Adrenal Glands↗
PubMed1995

Double-blind, placebo-controlled study of the long-term efficacy of carvedilol in patients with severe chronic heart failure.

BACKGROUND: Clinical trials have shown that beta-adrenergic blocking drugs are effective and well tolerated in patients with mild to moderate heart failure, but the utility and safety of these drugs in patients with advanced disease have not been evaluated. METHODS AND RESULTS: We enrolled 56 patients with severe chronic heart failure into a double-blind, placebo-controlled study of the vasodilating beta-blocker carvedilol. All patients had advanced heart failure, as evidenced by a mean left ventricular ejection fraction of 0.16 +/- 0.01 and a mean maximal oxygen consumption of 13.6 +/- 0.6 mL.kg-1.min-1 despite digitalis, diuretics, and an angiotensin-converting enzyme inhibitor (if tolerated). After a 3-week, open-label, up-titration period, 49 of the 56 patients were assigned (in a double-blind fashion using a 2:1 randomization) to receive either carvedilol (25 mg BID, n = 33) or matching placebo (n = 16) for 14 weeks, while background therapy remained constant. Hemodynamic and functional variables were measured at the start and end of the study. Compared with the placebo group, patients in the carvedilol group showed improved cardiac performance, as reflected by an increase in left ventricular ejection fraction (P = .005) and stroke volume index (P = .010) and a decrease in pulmonary wedge pressure, mean right atrial pressure, and systemic vascular resistance (P = .003, .002, and .017, respectively). In addition, compared with placebo, patients treated with carvedilol benefited clinically, as shown by an improvement in symptom scores (P = .002), functional class (P = .013), and submaximal exercise tolerance (P = .006). The combined risk of death, worsening heart failure, and life-threatening ventricular tachyarrhythmia was lower in the carvedilol group than in the placebo group (P = .028), but carvedilol-treated patients had more dizziness and advanced heart block. CONCLUSIONS: Carvedilol produces clinical and hemodynamic improvement in patients who have severe heart failure despite treatment with angiotensin-converting enzyme inhibitors.

Adrenergic beta-Antagonists↗
PubMed2000

Cardiovascular function in Omani children with sickle cell anaemia.

Systolic murmurs were detected in 22 (61%) of the 36 children with sickle cell anaemia (SCA) who completed the study. Cardiomegaly was detected in 14 (39%). Mean values of left and right ventricular dimensions were higher in SCA than in controls (p < 0.05). Left atrial chambers and aortic root dimensions followed the same pattern. The dilated cardiac chambers in SCA were not associated with any abnormality in systolic or diastolic left ventricular function nor with significant pulmonary hypertension.

Adolescent↗
PubMed1996

Atrial flutter mapping and ablation. I. Studying atrial flutter mechanisms by mapping and entrainment.

Endocardial mapping has led to a detailed knowledge of reentry mechanisms in atrial flutter. Multipolar and deflecting tip catheters allow recording local electrograms from multiple areas of the right atrium, and from the coronary sinus. In common flutter, with the typical "sawtooth" pattern, there is circular activation of the right atrium in a "counterclockwise" direction, descending in the anterior and lateral walls, and ascending in the septum and posterior wall. Superior and inferior vena cava, linked by a "line" of functional block in the posterolateral wall, make the central obstacle for circular activation. The cranial and caudal turning points are the atrial "roof," and the isthmus between the inferior vena cava and the tricuspid valve. Complex conduction patterns, probably including slow conduction are detectable in the low septal area, around the coronary sinus. Atypical flutter, without the sharp negative deflections of common flutter, sometimes shows circular activation in the right atrium, rotating in the opposite direction of common flutter (clockwise). Other atypical flutters show no circular right atrial activation, and only partial data from coronary sinus activation, combined with the response to atrial stimulation (entrainment) allow the diagnosis of left atrial reentry, without a precise delimitation of the circuits. In patients having undergone cardiac surgery, atypical flutter may be based on reentry around surgical scars. To our knowledge, the mechanism of type II flutter has not been disclosed in humans.

Atrial Flutter↗
PubMed1985

The beneficial effect of amrinone on acute drug-induced heart failure in the anaesthetised dog.

Amrinone, a positive inotropic-vasodilator agent, was administered to anaesthetised dogs in an attempt to reverse heart failure induced by drugs possessing negative inotropic properties. Propranolol, a beta-adrenergic blocker; verapamil, a calcium slow-channel blocker procainamide, a type 1 antiarrhythmic agent; or sodium pentobarbital, a barbituate; administered as a bolus injection and/or infusion, produced a sustained depression in canine cardiac function. Cardiac depression was characterised by a greater than 40% reduction in cardiac contractile force (CF) and maximum left ventricular pressure development (LV dp/dtmax), a 30 to 50% reduction in cardiac output (CO) and concomitant increases in mean central venous or mean right atrial blood pressures (CVP, RAP, respectively). Amrinone, when administered intravenously as a bolus injection (1 or 3 mg X kg-1) plus an infusion (0.03 or 0.1 mg X kg-1 X min-1) reversed the depression in cardiac function by increasing CF, CO and LV dp/dtmax and decreasing preload CVP or RAP in all four drug-induced failure models. Due to the vasodilator properties of amrinone, afterload, total peripheral resistance (TPR), was reduced in verapamil and procainamide failures as well as in propranolol failure, the only model where TPR increases. In another model of heart failure, in which ouabain-induced arrhythmias preceded procainamide toxicity, amrinone was also an effective cardiotonic agent. Ouabain's inotropic effect was studied in propranolol-induced heart failure. Although an increase in LV dp/dtmax and a decrease in CVP were noted, ouabain (40 micrograms X kg-1 iv) increased TPR and had little effect on the depression in CF and CO. Drug-induced models of heart failure were useful pharmacological tools for evaluating the cardiotonic agent's ability to overcome severe cardiac depression. In propranolol-, verapamil-, procainamide-, and pentobarbital-induced cardiac toxicity, amrinone could be of therapeutic value.

Aminopyridines↗