Transesophageal echocardiography after orthotopic heart transplantation

Complete atrioventricular cardiac transplantation: improved performance compared with the standard technique

BACKGROUND

There has been renewed clinical interest in an alternative technique to orthotopic cardiac transplantation involving six anastomoses: left pulmonary veins, right pulmonary veins, inferior vena cava, pulmonary artery, aorta, and superior vena cava (complete technique). In this study, the results of the complete technique are compared with those of the standard operation (ventricular transplantation with atrioplasty).

METHODS

Dogs were used for ten acute standard and ten acute complete atrioventricular transplantations. There were no significant differences in the baseline cardiac function (preload-independent right and left ventricular recruitable stroke work), bypass times, and cardiac ischemic times between the two groups.

RESULTS

After transplantation, sinus rhythm was preserved after all ten complete and after only one standard transplantation but no significant hemodynamic differences were observed. The right and left ventricular preload-independent recruitable stroke work in the complete group and the left ventricular preload-independent recruitable stroke work in the standard group were conserved after transplantation, but the right ventricular preload-independent recruitable stroke work decreased by 39% +/- 8% (p < 0.05) in the standard group. There was also a significant decrease in the rate of biventricular filling in the standard group after transplantation.

CONCLUSIONS

Complete atrioventricular transplantation is a feasible alternative technique and conserves normal sinus rhythm. The ischemic and bypass times are comparable for both methods. The insignificant change in the rate of biventricular filling in the dogs undergoing the complete technique indicates right and left ventricular diastolic function may be conserved after transplantation.

Orthotopic cardiac transplantation: a comparison of standard and bicaval Wythenshawe techniques

We describe an alternative technique for orthotopic cardiac transplantation (bicaval Wythenshawe technique), which maintains the right and left atrial anatomy. We compared the new bicaval technique with the conventional (Lower and Shumway) technique of orthotopic cardiac transplantation to identify any beneficial physiologic and clinical outcomes resulting from maintaining the normal anatomy. Seventy-five patients were randomized on an alternate basis to two groups: group A (n = 40) had orthotopic cardiac transplantation with the bicaval technique and group B (n = 35) had conventional orthotopic heart transplantation. All patients were studied with transthoracic echocardiogram, endomyocardial biopsies, and measurement of intracardiac pressures 1, 4, and 12 weeks after transplantation. There were no statistically significant differences in the demographic profile, ischemic time, bypass time, implantation time, transpulmonary gradient, or pulmonary vascular resistance between the two groups. The hemodynamic data were collected in the absence of histologic signs of rejection. In group A right atrial pressure (mean 3.6 mm Hg) was significantly lower (p < 0.03) than in group B (mean 8.8 mm Hg). The right atrial a wave was recorded in 38 patients in group A compared with seven patients in group B (p = 0.041). Atrial tachyarrhythmias occurred in two patients in group A compared with 11 in group B (p < 0.016). Temporary pacing was required in 10 patients in group A and 16 patients in group B (p = 0.034). Four cases of mitral regurgitation (all mild) were detected in group A in comparison with 12 cases (10 mild, 2 severe) in group B (p = 0.008). The mean ejection fraction in the first week after transplantation was 58% in group A and 46% in group B (p = 0.5). In the first 3 months the need for diuretics was less in group A (mean dose 80.8 mg furosemide daily) than in group B (mean dose 134 mg furosemide daily in the first week increasing to 160 mg furosemide daily). Hospital stay was shorter in group A (mean 23 days) than in group B (mean 27 days) (p < 0.015). There were no early deaths as a result of right ventricular failure in group A (n = 0/40) compared with four (n = 4/35; 9%) in group B (p < 0.034). This difference suggests that bicaval orthotopic cardiac implantation is associated with a lower right atrial pressure, a lower likelihood of atrial tachyarrhythmias, less need for pacing, less mitral incompetence, a lower diuretic dose, and a shorter hospital stay.(ABSTRACT TRUNCATED AT 400 WORDS)

Right ventricular function early after total or standard orthotopic heart transplantation

Right ventricular failure after orthotopic heart transplantation (OHT) is classically related to preoperative pulmonary hypertension. However, the role of the enlarged atria in right ventricular dysfunction after OHT remains unclear. For that purpose, the right ventricular function in the first 2 days after OHT was compared in two groups of transplant recipients: 11 patients who underwent standard OHT (group I) and 9 patients who underwent total OHT, which consisted of total excision of both the left and right atria and OHT of an intact donor heart with its atria as well as its ventricle (group II). Right ventricular ejection fraction, cardiac index, and right-sided pressures were recorded at baseline and 4, 8, 12, 24, and 48 hours after OHT using a Swan-Ganz catheter with a rapid-response thermistor. Right ventricular function parameters did not differ between groups; they were characterized by a decrease in right ventricular ejection fraction and an increase in right ventricular end-diastolic volume index whereas cardiac index and right-sided pressures remained normal or slightly increased. Ischemic time (177 +/- 41 minutes in group I versus 178 +/- 39 minutes in group II) and preoperative pulmonary vascular resistance (1.9 +/- 0.7 Wood units in group I versus 3.0 +/- 1.5 Wood units in group II) were not different between groups. These results suggest that the anatomic and physiologic advantages offered by the modified technique of OHT had no clinical relevance in this group of patients with low preoperative pulmonary vascular resistances when compared with a group of patients who underwent transplantation with the standard technique.(ABSTRACT TRUNCATED AT 250 WORDS)

The role of echocardiography in heart transplantation

Echocardiography has gained increasing importance as an imaging modality in the care of the cardiac transplant recipient. Its utility in detecting the complications of transplantation, with special reference to the diagnosis of rejection and graft arteriosclerosis, is discussed. On the basis of a review of the current literature, an outline for serial echocardiographic studies is proposed.

Transesophageal echocardiography in infants and children: use and importance in the cardiac intensive care unit

Recent development of small diameter (7 mm) biplane transesophageal echocardiography (TEE) probes has extended the select application of TEE to neonates, infants, and small children. We reviewed indications and uses for TEE in our neonatal and pediatric cardiac intensive care units over a 2-year period. Sixty-six TEE studies were performed in preoperative and postoperative settings in the intensive care unit after standard transthoracic studies. Age and weight of subjects ranged from 1 day to 16 years (mean 19 months) and 2.5 to 52 kg (mean 8.3 kg), respectively. Eighty-three percent of studies were performed in the immediate postoperative period after correction or palliation of congenital heart disease (including transposition of the great arteries, tetralogy of Fallot, atrioventricular septal defect, right ventricular conduit revision, Glenn shunt, and neonatal orthotopic heart transplantation). TEE advantages included unobstructed echo windows, particularly in postoperative settings of open sternum or high ventilatory support. Biplane imaging and Doppler provided additional hemodynamic information not otherwise detectable by noninvasive means. Posttransplant left and right ventricular function was immediately assessable. Overall findings included: residual shunts 24%, valvar insufficiencies 43%, residual gradients 4%, and left ventricular function or wall motion abnormalities 12%. TEE is a useful noninvasive adjunct in intensive care management of pediatric cardiac patients.