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The frequency of right-to-left shunt through a patent foramen ovale is increased in hemodynamically stable patients without preexisting cardiopulmonary disease with acute pulmonary embolism. This is associated with a greater degree of perfusion abnormalities as quantified by perfusion scan and the presence of tricuspid regurgitation.
Right ventricular (RV) dysfunction may occur due to increased RV afterload and, hence, might also contribute to the decrease in cardiac output following institution of PEEP in patients with adult respiratory distress syndrome (ARDS). To test this hypothesis, the authors examined the influence of PEEP on local and global RV function in 12 anesthetized dogs with experimental ARDS (eARDS) induced by pulmonary microembolization with glass beads and oleic acid. Local RV function was analyzed in the RV inflow tract (RVIT) and RV outflow tract (RVOT) by assessing both diastolic segment length, systolic segment shortening, and segment work (sonomicrometry). Global RV contractility was quantified by measuring maximum rate of pressure rise (dRVP/dtmax) and maximum velocity of contractile element shortening (Vmax). In eARDS, despite a fivefold increase in pulmonary vascular resistance, there was no change in cardiac index (CI), global RV contractility, RVIT and RVOT work, and RVIT shortening, whereas RVOT shortening decreased from 12.4 to 7.4% (P less than 0.01). Diastolic segment length increased in RVIT (P less than 0.05) but not in RVOT. PEEP of 10 cmH2O did not alter global RV contractility, RVIT and RVOT shortening, and RVIT work but reduced RVOT work (-35%; P less than 0.01) and CI (-11%; P less than 0.001). Cardiac index further decreased during PEEP of 20 cmH2O (-38%; P less than 0.001), while global RV contractility remained intact despite decreased RVIT and RVOT shortening (-32% and -69%; P less than 0.05) and work (-26% and -59%; P less than 0.01) in the presence of reduced fiber preload in both regions. From these findings, it was concluded that 1) the decreased CI during mechanical ventilation with PEEP at constant right ventricular end-diastolic pressure (RVEDP) is not caused by depressed global RV contractility in dogs with eARDS and a normal myocardium prior to insult. Decreased diastolic segment length and segment shortening during PEEP suggest that 2) PEEP reduces stroke volume by the Starling mechanism rather than by ischemia of the RV free wall. Finally, regionally incongruent changes of fiber preload indicate that 3) local differences in RV wall compliance are likely to occur subsequent to eARDS and PEEP.
This work presents a technique to improve the identification of late potentials (LP) in patients affected by greater arrhythmogenic right ventricular disease (GARVD). Several authors have documented the correlation between GARVD and LP by means of time domain analysis. Moreover, the high incidence of bundle branch block in patients affected by GARVD suggests LP analysis in the frequency domain be performed. The method of spectral mapping of the ECG with Fourier transform was adopted. This consists in dividing the ST segment into 25 subsegments and estimating their frequency components by means of the fast Fourier transform. Recently, it was documented that this technique suffers from poor reproducibility of results. Low reproducibility is the consequence of an improper localization of the analysed QRS segments. An algorithm to increase the QRS end point identification reproducibility is proposed. An optimal QRS filter was adopted as well as a technique based on the Hilbert transform. This technique allowed the reliability of the normality factor estimates to be improved. The computed normality factors on the XYZ leads and on the vector magnitude were used to classify patients and healthy subjects; 28 patients affected by greater arrhythmogenic right ventricular disease and 35 healthy subjects were analysed in the study. High sensitivity was obtained with respect to GARVD and clinical sustained ventricular tachycardia by means of a cluster analysis technique. By applying the technique proposed in this paper the identification of LP in GARVD was increased from 47% to 88%, when clinical sustained ventricular tachycardia was documented, whereas in patients affected by GARVD but not prone to sustained ventricular tachycardia LP identification increases from 18% to 64%.
The aim of the study was to compare the contractile response to ryanodine of human heart preparations taken from right and left ventricles of patients affected by idiopathic (IDCM) and secondary (SCM) end-stage dilated cardiomyopathies. Right and left ventricle myocardial strips were obtained from hearts of patients undergoing orthotopic heart transplantation and suspended in an oxygenated bath (T = 35 degrees C; stimulation frequency = 0.5 Hz). After an equilibration period, a cumulative dose-response curve for contractility (peak tension) was obtained with ryanodine (0.5, 1, 2, 4, 8, 16, 32, 64 microM). Basal contractility was not significantly different between right and left ventricles or between IDCM and SCM preparations. Ryanodine reduced peak myocardial tension but failed to completely suppress it, even at concentrations which achieved maximum effect. Ryanodine effect still persisted after a 45'-60' washout. The concentration-effect curves from IDCM right ventricle, IDCM left ventricle, SCM right ventricle and SCM left ventricle were compared: IDCM left ventricle was less sensitive to ryanodine than IDCM right ventricle and SCM left ventricle, while no difference was detectable between SCM left ventricle and SCM right ventricle. Thus, the overall sensitivity ranking was: IDCM left ventricle < IDCM right ventricle = SCM right ventricle = SCM left ventricle. IDCM left ventricle showed, in addition, a biphasic response with a shift from negative to positive inotropic effect at concentrations higher than approximately 10 microM. These findings indicate that the cardio-depressant effect of ryanodine, a drug which interferes with intracellular Ca release from the sarcoplasmic reticulum, differs quantitatively and qualitatively in IDCM left ventricle from both IDCM right ventricle and SCM left ventricle. This suggests that some specific alteration in the intracellular Ca signalling in IDCM exists and, from a methodological point of view, stresses the need for a "bi-ventricular" approach to studying biochemical and functional abnormalities of advanced congestive heart failure.
Scleroderma is reported to have numerous cardiac manifestations. Right ventricular failure (RVF) is a well-recognized cardiac complication of scleroderma and most often is related to underlying pulmonary hypertension (PH). Causes of PH include both interstitial lung disease and pulmonary artery vasculopathy. Direct involvement of the ventricle by myocardial fibrosis or coronary vasospasm could also cause a diffuse bilateral cardiomyopathy. We describe a case of predominant RVF in the absence of significant PH in a patient with longstanding scleroderma.
Severe pulmonary thromboembolism has been occasionally reported during orthotopic liver transplantation, with fatal outcomes occurring in about 50% of cases because of low cardiac output and multiple organ failure. Perioperative alterations in coagulation, insertion of pulmonary artery and other invasive catheters, administration of antifibrinolytic agents, and repeated ischemic insults may all promote the formation of intravascular/cardiac blood clots. We present a case of intraoperative right ventricular failure associated with the presence of a large thrombus wrapped around the pulmonary artery catheter. Identification of risk factors for intraoperative pulmonary thromboembolism warrants a prophylactic medical approach including selective blood component therapy and administration of antifibrinolytics guided by bedside coagulation tests as well as noninvasive hemodynamic monitoring.
BACKGROUND: The purpose of this study was to describe our institutional experience in using inhaled prostacyclin as a selective pulmonary vasodilator in patients with pulmonary hypertension, refractory hypoxemia, and right heart dysfunction after cardiothoracic surgery. METHODS: Between February 2001 and March 2003, cardiothoracic surgical patients with pulmonary hypertension (mean pulmonary artery pressure >30 mm Hg or systolic pulmonary artery pressure >40 mm Hg), hypoxemia (PaO(2)/fraction of inspired oxygen <150 mm Hg), or right heart dysfunction (central venous pressure >16 mm Hg and cardiac index <2.2 L.min(-1).m(-2)) were prospectively administered inhaled prostacyclin at an initial concentration of 20,000 ng/mL and then weaned per protocol. Hemodynamic variables were measured before the initiation of inhaled prostacyclin, 30 to 60 minutes after initiation, and again 4 to 6 hours later. RESULTS: One hundred twenty-six patients were enrolled during the study period. At both time points, inhaled prostacyclin significantly decreased the mean pulmonary artery pressure without altering the mean arterial pressure. The average length of time on inhaled prostacyclin was 45.6 hours. There were no adverse events attributable to inhaled prostacyclin. The average cost for inhaled prostacyclin was 150 US dollars per day. Compared with nitric oxide, which costs 3000 US dollars per day, the potential cost savings over this period were 681,686 US dollars. CONCLUSIONS: Inhaled prostacyclin seems to be a safe and effective pulmonary vasodilator for cardiothoracic surgical patients with pulmonary hypertension, refractory hypoxemia, or right heart dysfunction. Overall, inhaled prostacyclin significantly decreases mean pulmonary artery pressures without altering the mean arterial pressure. Compared with nitric oxide, there is no special equipment required for administration or toxicity monitoring, and the cost savings are substantial.
An artificial lung may offer a bridge to recovery or transplant. Utilizing our recently developed paracorporeal artificial lung (PAL) in survival studies in sheep, we critically review our perioperative/anesthetic protocol. Adult Suffolk ewes (n = 15) underwent general anesthesia induced by ketamine (7-15 mg/kg, im) and isoflurane by mask, then intubated and maintained by 4.0-5.0% isoflurane titrated to mean arterial pressure (MAP) 70-110 mm Hg. After a latissimus-sparing thoracotomy and systemic heparinization (200 IU/kg), arterial grafts were anastomosed to the proximal and distal main pulmonary artery in an end-of-graft to side-of-artery fashion. A snare was passed around the pulmonary artery between anastomoses. When the snare was tightened, full pulmonary blood flow was diverted through the cannulae and immediately through the PAL. Perioperative crystalloids included a 500-mL prime, lactated Ringer's (LR) titrated to CVP 5-7 mm Hg, and a heparin infusion (activated clotting time [ACT] 250-300 s). Buprenorphine (0.3 mg im tid) controlled postoperative pain. Hemodynamic parameters, arterial blood gases (ABGs), and ACTs were measured every 6 h. Thirteen of 15 sheep survived the operation and were extubated in less than 20 min. Two groups were studied for up to 7-day survival. Both groups underwent immediate connection to the PAL diverting full pulmonary blood flow. Group 1 (n = 8) underwent immediate connection to a rigidly housed PAL, and 4 of 8 demonstrated immediate right heart failure. In Group 2 a compliance chamber was added to the PAL inflow, and 6 of 7 had stable hemodynamic function for the duration of the study. Incremental improvements in the PAL and our anesthetic and perioperative care have resulted in reliable survival in adult sheep allowing for artificial lung development.
BACKGROUND: Lung transplantation is a valuable therapeutic option for selected patients with end-stage pulmonary disease. However, this treatment is complicated by ischaemia-reperfusion injury (IRI) of the lung in 10-20% of the recipients. We developed an unilateral porcine lung transplant model to study IRI and describe our experience with two different arterial anastomotic techniques. MATERIAL & METHODS: Twenty four domestic pigs [n = 6 x (donor + recipient)/group] were used in this study. Donor lungs were harvested using an antegrade flush with cold Perfadex and stored in the same solution for +/- 8 hours. Recipient animals underwent a left thoracotomy. After native pneumonectomy, the left donor lung was transplanted in the following order: 1. left atrial cuff; 2. bronchus; 3 pulmonary artery. 2 The outcome in recipients from historical groups differing in anastomotic technique was compared. An end-to-end anastomosis on the left pulmonary artery was performed in group I versus a patch anastomosis on the main pulmonary artery in group II. One hour after reperfusion, the right pulmonary artery and main bronchus were ligated forcing the recipient to survive on the transplanted lung only. The animals were further observed for 6 hours. RESULTS: Survival 6 hours after exclusion of the right lung was 33% (2/6) in group I versus 83% (5/6) in group II. Animals in group I died of right heart failure manifested by acute dilation of the right ventricle following ligation of the hilum of the right lung. CONCLUSION: Single lung transplantation with exclusion of the contralateral native lung is a critical model. Arterial end-to-end anastomosis resulted in an increased right ventricular afterload. The use of a patch technique improved the compliance of the arterial anastomosis and decreased early mortality. This transplant model is currently used in our laboratory to assess new methods for pulmonary preservation.
Three patients with typical histological signs of arrhythmogenic right ventricular dysplasia progressed to fulminating heart failure in 1 case and unexplained sudden death in the other two. There were signs of superacute myocarditis in the first case, previous healed pericarditis in the second and chronic myocarditis in the third case. These cases suggested the presence of an inflammatory process complicating the substrate of the dysplasia. Arrhythmogenic right ventricular dysplasia seems to be a developmental defect which is complicated in 50 to 70% of patients, according to a review of 74 cases reported in the literature, by a varying degree of myocarditis suggesting particular susceptibility of these patients to infection and explaining the presence of unusual amounts of fibrous tissue in some and the so called "progressive" nature of the disease in other patients.
Metastatic hepatocellular carcinoma (HCC) to the right atrium occurs rarely and may lead to lethal perioperative complications. A 61-year-old female who was about to undergo operation for resection of a right intraatrial tumor thought possibly to be metastatic hepatocellular carcinoma met with sudden protrusion of the tumor from the right atrial wall that sank into the right ventricle during induction of anesthesia. Right ventricular outflow tract obstruction developed and was quickly diagnosed by transesophageal echocardiography. Emergent cardiopulmonary bypass was rushed on the spot and the surgery was completed smoothly. Here we discuss the possible causes of the event and we recommend that special attention should be paid to the anesthetic techniques and proper precaution should be taken in the face of such a risky surgery.
We describe a case in which a discrete atretic segment of the right pulmonary artery (due to a Blalock-Taussig shunt) was reconstructed using a new radiofrequency system, balloon dilation, and stent implantation in an 18-month-old patient. The shunt was coil-occluded. The technique and applications of this novel approach are discussed.
OBJECTIVE: Acute respiratory distress syndrome (ARDS) is frequently associated with increased pulmonary vascular resistance and thus with systolic load of the right ventricle. We hypothesized that levosimendan, a new calcium sensitizer with potential pulmonary vasodilator properties, improves hemodynamics by unloading the right ventricle in patients with ARDS. DESIGN: Prospective, randomized, placebo-controlled, pilot study. SETTING: Twenty-two-bed multidisciplinary intensive care unit of a university hospital. PATIENTS: Thirty-five patients with ARDS in association with septic shock. INTERVENTIONS: Patients were randomly allocated to receive a 24-hr infusion of either levosimendan 0.2 microg/kg/min (n = 18) or placebo (n = 17). Data from right heart catheterization, cardiac magnetic resonance, arterial and mixed venous oxygen tensions and saturations, and carbon dioxide tensions were obtained before and 24 hrs after drug infusion. MEASUREMENTS AND MAIN RESULTS: At a mean arterial pressure between 70 and 80 mm Hg (sustained with norepinephrine infusion), levosimendan increased cardiac index (from 3.8 +/- 1.1 to 4.2 +/- 1.0 L/min/m) and decreased mean pulmonary artery pressure (from 29 +/- 3 to 25 +/- 3 mm Hg) and pulmonary vascular resistance index (from 290 +/- 77 to 213 +/- 50 dynes/s/cm(5)/m(2); each p < .05). Levosimendan also decreased right ventricular end-systolic volume and increased right ventricular ejection fraction (p < .05). In addition, levosimendan increased mixed venous oxygen saturation (from 63 +/- 8 to 70 +/- 8%; p < .01). CONCLUSIONS: This study provides evidence that levosimendan improves right ventricular performance through pulmonary vasodilator effects in septic patients with ARDS. A large multiple-center trial is needed to investigate whether levosimendan is able to improve the overall prognosis of patients with sepsis and ARDS.
The assessment of pulmonary artery pressure, right ventricular function, right ventricular filling pressure, and tricuspid regurgitation provides invaluable information in the care of patients with pulmonary vascular disease. Echocardiography provides a rapid, noninvasive, portable, and accurate method to evaluate these parameters and also provides information on left ventricular and valvular function. Echocardiography has therefore become one of the most commonly performed diagnostic studies in patients with pulmonary vascular disease, and the technique's applications in this area are likely to grow. This article presents an overview of the current uses of echocardiography in pulmonary vascular disease and pulmonary hypertension.
We report a patient in whom there was right ventricular outflow tract obstruction by extended metastasis from esophageal cancer. A 65-year-old man was admitted to the hospital for evaluation of recent onset of weight loss and heart murmur. Esophagogram and endoscopy showed a 10-cm, ulcerative, infiltrative esophageal cancer. This esophageal cancer was histologically proven to be a squamous cell carcinoma. To assess the cardiac metastasis, echocardiography, magnetic resonance imaging, coronary angiography, and endomyocardial biopsy were performed. The magnetic resonance imaging, echocardiography, and right ventriculography revealed a 7-cm lobulated mass extending to the right ventricular outflow tract, right ventricle, septum, and anterior wall of the left ventricle. Interestingly, the feeding vessels of the tumor were identified by echocardiography and coronary angiography. Histologically, the cardiac tumor was proven to be have the same pathologic findings as esophageal cancer, compatible with carcinomatous metastasis.
This is a description of a rare complication of a pericardial cyst with spontaneous internal hemorrhage and following tamponade. The noninvasive diagnosis was done by transesophageal echocardiography and computed thoracic tomography. The cyst was thoracoscopically removed and pathologically examined. This case demonstrates a rare but important and life-threatening complication of mostly asymptomatic pericardial cysts.
The present review is focused on chronic RV pressure overload or Cor Pulmonale as it may occur in the setting of two distinct disorders: those associated with abnormal pulmonary gas exchange (hypoxemia and/or hypercapnia) where chronic obstructive pulmonary disease (COPD) is the leading cause, and those associated with pulmonary vascular obstruction where primary pulmonary hypertension (PDDH) is the representative example. The clinical curse, prognostic, implications, and therapeutic strategies differ considerably in these two clinical entities. Right ventricular failure (RVF) may adversely influence the natural history and prognosis of patients with diverse cardiopulmonary disorders. It has been long established that right ventricular (RV) ischemia, RV overload, and RV pressure overload, alone or in combination, are the main factors involved in the pathogenesis of RVF. From the pathophysiologic point of view, RVF of COPD is more a congestive type of failure, in which activation of renin-angiotensin system is involved. In PPH, a low cardiac output state is predominant and the precise mechanism of RVF remains unknown. Current evidence in favor of the pathogenetic role of ischemia, adrenergic overdrive, and genetic determination are all reviewed during the course.
INTRODUCTION: The effects of l-thyroxine (l-T(4)) replacement for subclinical hypothyroidism (SH) on right ventricle (RV) functions has not been previously studied by means of pulsed wave tissue Doppler imaging (PWTDI). We investigated the effects of l-T(4) therapy on RV function in patients with SH using PWTDI. PATIENTS AND METHODS: Fifty-three patients with newly diagnosed SH and 25 controls were evaluated by standard echocardiography and PWTDI. After euthyroidism was restored by l-T(4), measurements were repeated. Myocardial systolic wave (S(m)) velocity, isovolumic acceleration (IVA), myocardial precontraction time (PCT(m)), and PCT(m) to contraction time (CT(m)) ratio were calculated as systolic indices. Early (E(m)) velocity, late (A(m)) velocity, E(m) to A(m) ratio, and myocardial relaxation time (RT(m)) were determined as diastolic measurements. RESULTS: S(m) was similar in patients and controls, whereas IVA was significantly lower in patients with SH (P < 0.001). SH patients had significantly decreased E(m) velocity, whereas A(m) velocity and E(m) to A(m) ratio did not differ. PCT(m) and RT(m) were significantly longer, and PCT(m) to CT(m) ratio was significantly higher in patients (P = 0.002, P = 0.002, P < 0.001, respectively). S(m) velocities were similar before and after l-T(4) replacement, whereas IVA significantly increased after therapy (P < 0.001). E(m) tended to increase (P = 0.05), whereas A(m) and E(m) to A(m) ratio were not changed. PCT(m), PCT(m) to CT(m) ratio, and RT(m) decreased significantly (P < 0.001 for all). CONCLUSIONS: SH is associated with RV systolic and diastolic dysfunction, and l-T(4) treatment improves these abnormalities. PWTDI, especially IVA, may be a suitable tool for the early detection of RV systolic dysfunction.