Galal Ziady

Cardiac rhythm disturbances early after orthotopic heart transplantation: Prevalence and clinical importance of the observed abnormalities

To precisely define the incidence, type and consequences of cardiac arrhythmias early after heart transplantation, 25 cardiac transplant recipients were monitored continuously for 728 days from the day of surgery to discharge or death. A subset of 15 patients had sinus node function studies with overdrive suppression performed weekly at the time of endomyocardial biopsy. Results revealed sinus bradycardia in 10 patients (40%) and junctional bradycardia in 6 (24%). Supraventricular tachycardia in the form of atrial tachycardia, atrial fibrillation and atrial flutter occurred in 11 patients (44%). Ventricular tachycardia occurred in 15 patients (60%) and was nonsustained in all. Cardiac pacing for 1,403 h was used in nine patients with a pulse rate less than 50 beats/min; seven recovered and permanent pacing was instituted in two. In the subgroup that had sinus node function studies, seven patients were identified with clinical bradyarrhythmia; each had abnormal sinus node recovery time (greater than 1,400 ms) and abnormal corrected sinus node recovery time (greater than 525 ms) in at least one study. These seven patients also had a significantly prolonged ischemic time (236 +/- 26 versus 159 +/- 68 min, p less than 0.01). In conclusion, cardiac arrhythmias, particularly ventricular tachycardia and bradyarrhythmia, occur more commonly early after orthotopic heart transplantation than has previously been reported. Sinus node dysfunction due to prolonged organ ischemic time, antiarrhythmic drug use or surgical trauma, alone or in combination, may contribute to these arrhythmias.

Transesophageal echocardiography to evaluate patients with severe pulmonary hypertension for lung transplantation

The surgical approach to lung transplantation for patients with severe pulmonary hypertension will be dependent on the primary disease and specific cardiac anatomy. To determine the safety and utility of transesophageal echocardiography in the management of patients with severe pulmonary hypertension who are being evaluated for lung transplantation, we studied 48 consecutive patients, aged 38 +/- 11 years, with pulmonary artery systolic pressure of 70 mm Hg or greater. All patients previously underwent left and right heart catheterization, transthoracic echocardiography, and radionuclide ventriculography. Transesophageal echocardiography was tolerated well by all patients. Additional data that significantly altered surgical therapy was found in 12 of 48 patients (25%): proximal pulmonary artery thrombi (3), patent foramen ovale with significant right to left shunting (2), atrial septal defect (2), double-outlet right ventricle (2), ventricular septal defect (2), and exclusion of atrial septal defect (1). These findings were confirmed surgically in all patients except 3, who died awaiting transplantation. Transesophageal echocardiography is useful in the evaluation of patients with severe pulmonary hypertension.

Hemodynamic evaluation of porcine bioprostheses in the mitral position by Doppler echocardiography

Twenty-four patients with porcine bioprostheses in the mitral position were studied by Doppler echocardiography followed by cardiac catheterization within 24 hours. Doppler mean diastolic mitral valve gradient was calculated by a 3-point method and mitral valve area was determined by the pressure half-time method. Data from Doppler echocardiography and cardiac catheterization were compared. There was a strong correlation between Doppler echocardiography and catheterization-determined mean diastolic gradient: r = 0.9, standard error of estimate (SEE) = 1.4 mm/Hg (regression equation y = 0.63x + 1.41), p less than 0.001. There was also a strong correlation between Doppler echocardiography and catheterization-determined mitral valve area: r = 0.86, SEE = 0.18 cm2 (regression equation y = 0.64x + 0.52), p less than 0.001. Fourteen patients whose valvular function was considered normal by clinical evaluation had Doppler-calculated mean diastolic gradients of 4.5 to 9.5 mm Hg (mean 6.5 +/- 1.4); the Doppler-determined valve area was 1.15 to 2.0 cm2 (mean 1.54 +/- 0.3). Ten patients had a malfunctioning bioprosthesis, 7 had severe mitral regurgitation and 3 had stenosis. Valvular malfunction in all 10 patients was detected by Doppler echocardiography and confirmed by catheterization and angiocardiography. Nine patients underwent reoperation. Doppler hemodynamic evaluation of porcine bioprostheses in the mitral position provided noninvasive information comparable to that obtained by cardiac catheterization.

Outcome and complications of prolonged intraaortic balloon counterpulsation in cardiac patients

The risks and benefits of prolonged intraaortic balloon support for the management of refractory congestive heart failure and ischemia were studied in patients with end-stage heart disease who needed support for greater than or equal to 5 days. Fifty-two insertions were performed by the percutaneous femoral route in 49 patients. The duration of insertion ranged from 5 to 46 days (mean 11.3). Clinical outcome including hemodynamic parameters and complications were recorded. Mean systemic arterial pressure did not change with balloon insertion (74 +/- 19 vs 76 +/- 11 mm Hg; p = not significant). Both the mean pulmonary artery and pulmonary arterial wedge pressures decreased (33 +/- 8 to 26 +/- 9 mm Hg [p less than 0.01], and 25 +/- 8 to 17 +/- 6 mm Hg [p less than 0.01], respectively). Over time, both parameters tended to increase, but remained significantly less than those before insertion. Cardiac index increased from 1.6 +/- 0.4 to 2.2 +/- 0.5 liters/min/m2 on insertion and continued to increase to 2.7 +/- 0.5 liters/min/m2 (p less than 0.01) before removal. Definite balloon catheter infection developed in 7 patients, and hemorrhage occurred in an additional 7. Eleven patients had vascular compromise, with loss of pulse in 6, thrombosis of the femoral artery in 1, and pseudoaneurysm in 2. Lacerated femoral artery occurred in 1 patient, and mesenteric artery thrombosis in another. Twenty patients died from progressive heart failure and multiorgan system failure, and 19 survived to receive left ventricular assist device and heart transplantation. Only 10 patients were weaned off the balloon. In conclusion, prolonged intraaortic balloon pump support may be successfully used in end-stage heart disease.

Diastolic dysfunction in cardiac transplant recipients: An important role in the response to increased afterload

We evaluated the hemodynamic and functional response to acute elevations in left ventricular (LV) afterload in 22 recent recipients of cardiac transplants to determine whether abnormalities in LV diastolic function influence the response to this intervention. In seven patients (group 1) LV ejection fraction decreased significantly from baseline values (> or = 5%) during methoxamine infusion, whereas in 15 patients (group 2) LV ejection fraction was maintained. Peak filling rate was lower in group 1 versus group 2 (3.36 +/- 0.46 vs 4.23 +/- 0.68 end-diastolic volumes/sec, p < 0.01). In addition, patients in group 1 did not have LV dilatation during methoxamine (percentage change in end-diastolic counts, -3.4 +/- 6.9%) and had a large increase in pulmonary artery wedge pressure. In contrast, patients in group 2 had LV dilatation (percentage change in end-diastolic counts, +10.7 +/- 14.7%) and a smaller increase in pulmonary artery wedge pressure. There was a relationship between the baseline peak filling rate and the change in LV ejection fraction during methoxamine (r = 0.65, p = 0.001). Therefore in a subset of cardiac transplant patients, abnormalities in LV filling can have an impact on the response to increased afterload.

Tricuspid Flail Leaflets After Orthotopic Heart Transplant: A New Complication of Endomyocardial Biopsy

A case of tricuspid flail leaflets in a patient with orthotopic heart transplant is reported. The use of echocardiography to document the complication and its relationship to endomyocardial biopsy is presented.

Visualization of Coronary Artery Fistula with Transesophageal Echocardiography

Coronary artery fistulas are relatively uncommon and are usually initially suspected on auscultation of a continuous murmur. Long-term complications include congestive heart failure, endocarditis, ischemia, and atrial arrhythmias. The role of echocardiography in visualization and diagnosis of these fistulas is expanding. We report two cases in which transesophageal echocardiography was used to visualize and better define proximal coronary arteries and coronary artery fistulas.

Effects of acute alterations in left ventricular loading conditions on peak filling rate in the denervated (transplanted) ventricle

Peak filling rate is an indicator of left ventricular (LV) diastolic function. It is influenced by heart rate, loading conditions, sympathetic nervous system activity, ejection fraction and other factors. To determine the effect of altered loading conditions on peak filling rate, independent of heart rate and sympathetic nervous system activity, 12 patients were studied 3 weeks after orthotopic heart transplantation. Plasma catecholamine level, heart rate and ejection fraction were not changed by any maneuver. Nitroglycerin caused a decrease in pulmonary artery wedge pressure (9 +/- 2 to 6 +/- 1 mm Hg, p less than 0.001) and in absolute peak filling rate (46.0 +/- 3.0 to 42.8 +/- 2.5 kcts/s, p less than 0.01), but no change in normalized peak filling rate. Volume infusion increased pulmonary artery wedge pressure (9 +/- 2 to 12 +/- 2 mm Hg, p less than 0.001) and absolute peak filling rate (46.0 +/- 3.0 to 51.5 +/- 5.3 kcts/s, p less than 0.01), but peak filling rate normalized to stroke volume was unchanged. During nitroglycerin and volume infusions, there was a high correlation between changes in pulmonary artery wedge pressure and absolute peak filling rate (r = 0.82, p less than 0.001). With normalization of peak filling rate, these variables correlated less well. With methoxamine, 4 patients demonstrating systolic dysfunction had a decrease in absolute and normalized peak filling rate despite a large increase in pulmonary artery wedge pressure. The other 8 patients without systolic dysfunction had an increase in pulmonary artery wedge pressure with increased absolute but unchanged normalized peak filling rate.(ABSTRACT TRUNCATED AT 250 WORDS)

A Double-Blind Trial of Glycopyrrolate for Transesophageal Echocardiography

Glycopyrrolate is an anticholinergic agent used to dry oral secretions and has been advocated for routine use with transesophageal echocardiography (TEE). To evaluate the safety and efficacy of glycopyrrolate for this unique application, a prospective double-blind placebo-controlled study of glycopyrrolate was performed in 61 patients who were awake while undergoing TEE. Thirty patients were randomized to the standard dose of glycopyrrolate (0.2 mg intravenously), and 31 patients received 1 ml of saline solution as placebo. Intravenous midazolam was used for sedation in all but one patient. Heart rate, electrocardiogram, blood pressure, and oxygen saturation were continuously monitored before, during, and after TEE. The patients scored their comfort immediately after TEE and were interviewed at 24 hours for side effects. The operator scored the ease of performing the TEE. No complications occurred in either group. Changes in vital signs and oxygen saturation were similar in both groups. The operator ease and patient comfort was similar in both groups. A significantly higher incidence of the following side effects was observed at 24 hours in patients who received glycopyrrolate versus those who received placebo: sore throat, 63% versus 19%; dry mouth, 43% versus 6%; and urinary retention, 16% versus 0% (p < 0.05 for all). No benefit from glycopyrrolate was noted in operator ease or patient comfort. In conclusion, glycopyrrolate is not recommended for routine use when performing TEE on patients who are awake.

Effect of Verapamil on Ventricular Function: Studies in Denervated Human Heart

Verapamil has complex influences on ventricular function owing to its direct myocardial effects, vasodilation, and reflex activation of the sympathetic nervous system. To investigate the direct myocardial effects of verapamil in humans independent of reflex sympathetic stimulation, we administered the drug to 13 recent heart transplant recipients with denervated ventricles. Hemodynamics and radionuclide angiograms were recorded at baseline, with altered loading conditions, and after intravenous (i.v.) verapamil (median dose 4 mg). Left ventricular (LV) systolic and diastolic function was analyzed by systolic pressure-volume relations (SPVR) and peak filling rate (PFR), respectively. Verapamil caused a decrease in blood pressure (BP) and heart rate (HR) with increases in right atrial pressure (RAP 6 +/- 3-8 +/- 3, p < 0.01) and pulmonary artery wedge pressure (PAWP, 9 +/- 3-11 +/- 3 mm Hg, p < 0.01) pressures. LV ejection fraction (EF) decreased (69 +/- 7-66 +/- 8%, p < 0.02) in association with an increase in LV end-systolic counts (3.45 +/- 1.27 to 4.72 +/- 1.78 kcts, p < 0.001). In 11 of 13 patients, the SPV point after verapamil administration was decreased from the line established during altered loading conditions. PFR (4.05 +/- 0.81 to 4.11 +/- 0.76 EDV/s) was unchanged. In the denervated ventricle, verapamil has negative chronotropic and inotropic effects with minimal effects on PFR.