Sharo Raissi

Biventricular support in patients with profound cardiogenic shock: A single center experience

Options for managing heart failure patients with cardiogenic shock refractory to inotropic and intra-aortic balloon pump (IABP) therapy are limited. Ventricular assist devices (VADs) can bridge these patients to heart transplantation. However, controversy exists over whether extracorporeal membrane oxygenation (ECMO) before VAD placement is beneficial. We report our use of biventricular assist devices (BiVADs) as a direct bridge to transplant. Since July 1999, 19 Thoratec BiVADs were implanted for heart failure unresponsive to medical therapy. Patient ages ranged from 20 to 67 years. Causes of heart failure included idiopathic 32%, ischemic 26%, postcardiotomy 21%, and other 21%. All patients were in cardiogenic shock, and three were receiving cardiopulmonary resuscitation (CPR) before implant. Preimplant conditions included IABP 89%, mechanical ventilation 68%, three or more inotropes 84%, hyperbilirubinemia 59%, acute renal failure 63%, and hemodialysis 16%. Fifty-nine percent of patients bridged successfully to transplantation, with 90% posttransplant survival. Duration of BiVAD support ranged from 0 to 91 days, with two patients currently on support awaiting transplantation. Complications included bleeding requiring reoperation 26%, stroke 11%, infection (any positive culture) 68%, and cannula site infection 5%. The Thoratec BiVAD can successfully be used as a direct bridge to transplantation in heart failure patients with cardiogenic shock.

Effect of capacitor size and pathway resistance on defibrillation threshold for implantable defibrillators.

BACKGROUND The time constant of truncated exponential pulses used with implantable defibrillators is determined by the output capacitor size and defibrillation pathway resistance. The optimal capacitor size is unknown. METHODS AND RESULTS This study compared defibrillation threshold (DFT) for standard 120-microF capacitors (DFT120) and smaller 60-microF capacitors (DFT60) at implantation of cardioverter-defibrillators in 67 patients using epicardial electrodes (15 patients) or one of four transvenous electrode configurations (52 patients). Paired comparisons of DFT60 and DFT120 were made for 44 defibrillation pathways using monophasic pulses and for 53 pathways using biphasic pulses. Truncated exponential pulses with 65% tilt were used. Pooled data from all electrode configurations showed a significant inverse correlation between pathway resistance and the ratio of stored energy DFT60 to DFT120 (monophasic pulses: r = .75, P = .0001; biphasic pulses: r = .68, P = .0001). Data from all electrode configurations formed a continuum with 120-microF capacitors superior for low-resistance pathways and 60-microF capacitors superior for high-resistance pathways. For pathways with resistance < or = 40 omega, the modest advantage of 120-microF capacitors applied primarily to pathways with low DFTs: 8.2 +/- 6.1 versus 9.6 +/- 5.4 J (P = .001) for monophasic pulses and 4.1 +/- 2.8 versus 5.1 +/- 3.1 J (P < .02) for biphasic pulses. The greater advantage of 60-microF capacitors for pathways with resistance > or = 61 omega applied to pathways with higher DFTs: 12.4 +/- 4.3 versus 23.1 +/- 6.4 J (P = .0001) for monophasic pulses and 8.5 +/- 4.9 versus 12.5 +/- 6.4 J (P = .0001) for biphasic pulses. For pathways using monophasic 120-microF pulses versus 95% for 60-microF pulses. Similarly, the DFT was < or = 10 J for 48% of pathways using biphasic 120-microF capacitors versus 83% for 60-microF pulses. CONCLUSIONS In comparison with conventional 120-microF capacitors, 60-microF capacitors had clinically insignificant higher DFTs for low-resistance pathways and clinically important lower DFTs for high-resistance pathways. Optimal capacitance is inversely related to pathway resistance for clinical defibrillation pathways and waveforms.

Clinical experience with one hundred consecutive patients undergoing orthotopic heart transplantation with bicaval and pulmonary venous anastomoses

OBJECTIVE Our objective was to assess survival, need for pacemaker insertion, and rejection frequency with a new surgical technique of orthotopic heart transplantation using bicaval and pulmonary venous anastomoses. METHODS We retrospectively reviewed 100 consecutive patients who had orthotopic heart transplantation with this technique between July 1991 and September 1995. RESULTS The mean age was 57.0 +/- 11.1 years, with 51 patients being 60 years or older. The mean donor/recipient weight ratio was 0.92, and in 28 patients the ratio was less than 0.8. The early (30-day) survival was 100% and the 1- and 2-year survivals were 98% +/- 2% and 96% +/- 2%, respectively. Survival was not affected by age or by the duration of the OKT3 therapy (p > 0.2 for each of these parameters). The seven late deaths were due to infection (n = 2), graft atherosclerosis (n = 3), acute rejection (n = 1), and nonspecific graft failure (n = 1). No permanent pacemaker was required in the first 6 months after the operation, and all the patients were discharged in normal sinus rhythm. Freedom from treated rejection was significantly greater in patients with 7 days of OKT3 therapy than in patients with 14 days of therapy (p < 0.0001). CONCLUSIONS Orthotopic heart transplantation with bicaval and pulmonary venous anastomoses offers an improved alternative to the standard biatrial technique, with a 30-day mortality of 0,% in 100 consecutive patients, excellent intermediate-term survival, and elimination of the need for pacemaker insertion. More normal anatomic configuration and synchronous function of the atria may have contributed to these results.

Use of Cardiac Allografts With Mild and Moderate Left Ventricular Hypertrophy Can Be Safely Used in Heart Transplantation to Expand the Donor Pool

OBJECTIVES The purpose of this study was to evaluate outcomes of heart transplantation (HTx) and changes in left ventricular wall thickness (LVWT) post-HTx using donors with left ventricular hypertrophy (LVH). BACKGROUND Limited data are available on use of donor hearts with LVH in HTx. METHODS We reviewed 427 patients who underwent HTx: 62 received hearts with LVH (interventricular septum [IVS] or posterior wall [PW] thickness >or=1.2 cm) by echocardiography, and 365 received hearts without LVH. The median follow-up was 3.8 years (range 0 to 16.2 years). RESULTS Recipient age was 56 +/- 11 years and donor age was 30 +/- 12 years. Baseline recipient characteristics were similar in both groups. Donors with LVH were older (35 +/- 12 years vs. 29 +/- 12 years, p = 0.001) and had higher rates of intracranial hemorrhage (38% vs. 15%, p = 0.001). The LVWT was increased in the LVH group compared with LVWT in the non-LVH group (IVS: 1.28 +/- 0.18 cm vs. 0.85 +/- 0.19 cm, PW: 1.27 +/- 0.19 cm vs. 0.85 +/- 0.20 cm, p = 0.0001 for both groups). Mild LVH (1.2 to 1.3 cm) was found in 42%, moderate (>1.3 to 1.7 cm) in 53%, and severe (>1.7 cm) in 5% of donors with LVH. Left ventricular wall thickness regression occurred in both IVS and PW (1.28 +/- 0.18 cm vs. 1.10 +/- 0.13 cm vs. 1.13 +/- 0.14 cm, and 1.27 +/- 0.19 cm vs. 1.11 +/- 0.11 cm vs. 1.13 +/- 0.14 cm, at baseline, 1 year, and 5 years, respectively; p < 0.001 for change from baseline to 1 and 5 years for both locations). Patients with or without donor LVH had similar 1-year (3.5% vs. 9.5%, p = 0.2) and 5-year survival rates (84 +/- 5.9% vs. 70 +/- 2.7%, p = 0.07). CONCLUSIONS Short- and long-term survival rates and rates of LVH at follow-up were similar in both groups, suggesting that donor hearts with mild and moderate LVH can be safely used in HTx.

Optimal electrode configuration for pectoral transvenous intplantable defibrillator without an active can

A new 83 cm3 implantable cardioverter-defibrillator (ICD) designed for pectoral implantation has been implanted most frequently using right ventricular and superior vena cava (RV-->SVC) electrodes; a patch electrode (RV-->patch + SVC) has been added when necessary to decrease the defibrillation threshold (DFT). The goal of this prospective study was to compare biphasic waveform DFTs for 3 electrode configurations: RV-->patch, RV-->SVC, and RV-->patch + SVC in 25 consecutive patients. The patch was positioned in a left retro-pectoral pocket, and the SVC electrode was positioned with the tip at the junction of the SVC and innominate vein. In the first 15 patients, all 3 electrode configurations were tested in random order; in the last 10 patients, only the RV-->patch and RV-->patch + SVC configurations were tested. In the first 15 patients, the stored-energy DFT for the RV-->SVC configuration (15.2 +/- 7.7 J) was higher (p < 0.001) than the DFT for the RV-->patch configuration (11.3 +/- 6.2 J) and the RV-->patch + SVC configuration (10.0 +/- 5.8 J). For all 25 patients, the DFT was lower for the RV-->patch + SVC configuration (9.7 +/- 5.1 J) than for the RV-->patch configuration (12.4 +/- 6.6 J, p = 0.005). The pathway resistance was highest for the RV-->patch configuration (72 +/- 9 omega), lower for the RV-->SVC configuration (63 +/- 6 omega, p < 0.01), and lowest for the RV-->patch + SVC configuration (46 +/- 3 omega, p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Phase-contrast cine MR angiography detection of thoracic aortic dissection

Purpose: To assess prospectively the accuracy of phase-contrast cine MR angiography in the detection of thoracic aortic dissection with operative correlation. Materials and methods: One hundred and ninety-seven symptomatic patients suspected of having thoracic aortic dissection or aneurysm as well as 13 patients suspected of having thoracic aortic coarctation and 20 asymptomatic normals (as controls) were examined prospectively with phase-contrast cine MR angiography on a 1.5-T MR imager. Seventy-eight of these patients had operative correlation, and only these 78 patients were included in the statistical analysis. Results: There were 51 true positive and 27 true negative findings of thoracic aortic dissection in this study for an accuracy of 100%. Conclusion: Phase-contrast cine MR angiography is an accurate non-invasive imaging technique for evaluating patients suspected of having thoracic aortic dissection.

Rapid Extension of Left Adrenocortical Carcinoma into the Right Atrium

Adrenocortical carcinoma is a rare tumor which can extend into the right heart via the inferior vena cava. We describe a case of a 26-year-old woman who had progressive shortness of breath, intermittent chest pain, and peripheral edema. A two-dimensional echocardiogram on hospital admission showed a large multinodular mass in the right atrium which extended into the inferior vena cava. Further studies showed that this mass was adrenocortical carcinoma. An echocardiogram performed 3 weeks before admission was completely normal. It appears that an adrenocortical carcinoma is capable of rapid growth up the inferior vena cava and into the right atrium.

Transesophageal echocardiographic identification of an abdominal aortic pseudoaneurysm complemented by a transpulmonary echo contrast agent.

Pseudoaneurysm of the abdominal aorta, a rare complication after traumatic injuries, represents a diagnostic challenge for which sophisticated imaging modalities are often used for its early identification. We describe a case in which transesophageal echocardiographic examination complemented by a transpulmonary echo contrast agent was useful not only in demonstrating the pseudoaneurysm, but in helping to localize the intravascular communication between the aorta and the pseudoaneurysm.