Morton R. Rinder

Effects of endurance exercise training on left ventricular systolic performance and ventriculoarterial coupling in patients with coronary artery disease

BACKGROUND Endurance exercise training can increase left ventricular (LV) ejection fraction during dynamic exercise in coronary artery disease. This adaptation may be mediated by altered cardiac loading conditions rather than an improvement in intrinsic LV systolic function. To minimize these confounding effects, we used isometric handgrip exercise to assess the training-induced changes in LV systolic function and ventriculoarterial coupling. METHODS Twenty-six patients (52 +/- 2 years of age) trained for 12 months. LV function was assessed with radionuclide ventriculograpy. RESULTS LV systolic reserve (the change in LV ejection fraction from rest to handgrip exercise) increased from -7.32 +/- 1.2 to -3.4 +/- 1.1 (P =. 033) without acute changes in end-diastolic volume or the effective arterial load. LV end-systolic elastance increased 37% (P =.039) during handgrip exercise. Resting end-diastolic volume increased and the effective arterial load decreased after training. CONCLUSIONS Data suggest that in coronary artery disease adaptations to exercise training include a lower effective arterial load and an increase in EDV at rest, with an improvement in LV systolic function detectable only during afterload stress.

Thrombin injection to treat pseudoaneurysm of internal mammary artery bypass graft: A case report

We report a patient with pseudoaneurysm of internal mammary artery bypass graft that was treated with local thrombin injections by percutaneous approach. The patient is a 72-year-old female with extensive history of coronary artery disease. She underwent coronary artery bypass surgery initially in 1984 and redo bypass surgery in 1998 (with placement of a sequential LIMA graft to second diagonal and left anterior descending artery). A year after the bypass surgery, she was readmitted to the hospital for evaluation of transient ischemic attacks. During diagnostic work-up, cardiomegaly was noted on a routine chest X-ray, prompting further cardiac evaluation. Diagnostic cardiac catheterization revealed a large pseudoaneurysm at the site of insertion of LIMA graft into the second diagonal artery (Fig. 1). Cardiac MR imaging quantified the size of the lesion to be about 2.5 2.3 cm (Figs. 2 and 3). Given the large size of the pseudoaneurysm, the patient was at higher risk for catastrophic rupture. A percutaneous transthoracic approach to treat the pseudoaneurysm by local thrombin injection was felt to be not feasible due to the location of the pseudoaneurysm, with substantial risk for injury to internal organs. In addition, the prior cardiac surgeries placed the patient at high risk for bleeding due to adhesions if repeat cardiac surgery was attempted. Therefore, percutaneous coronary artery intervention was felt to be the best approach to treat this condition. An attempt was made to thrombose the pseudoaneurysm using a surpass perfusion balloon. An IMA guiding catheter was placed at the ostium of the internal mammary artery to gain access to the pseudoaneurysm. The perfusion balloon was placed at the entrance site into the pseudoaneurysm and was inflated at 1.5 atm for about 30 min. Contrast angiography and MRI studies at the end of the procedure demonstrated continued patency of the pseudoaneurysm with brisk flow (Figs. 4 and 5). About 2 months later, an attempt was made to coil-embolize the pseudoaneurym percutaneously. An IMA guiding catheter was placed at the ostium of the internal mammary artery to gain access to the pseudoaneurysm. A double-marker Tracker catheter was placed into the pseudoaneurysm and about 20 GDC coils of various sizes were delivered into the aneurysm. Coil sizes varied from 5 mm 15 mm to 20 mm 30 mm. The procedure was terminated when further coils could not be introduced into the pseudoaneurysm. Angiography with the Tracker catheter in situ showed no filling of the pseudoaneurysm. However, on removing the Tracker catheter, the pseudoaneurysm continued to fill, suggesting the presence of at least two loculated sacs (Fig. 6). A repeat cardiac MRI 1 month later demonstrated the continued presence of pseudoaneurysm with an increase in size to 3.5 cm 2.3 cm (Fig. 7). In view of the continued expansion of the pseudoaneurysm, a decision was made to proceed with direct local thrombin injection. An IMA guiding catheter was placed at the ostium of the internal mammary artery to gain access to the pseudoaneurysm. A target Tracker infusion catheter was placed in the pseudoaneurysm and 2,000 international units of thrombin in 4 cc of saline was infused into the cavity. This injection was repeated again after demonstration of continued flow into the pseudoaneurysm. During the procedure, blood flow into the distal LAD was compromised but responded quickly to administration of intracoronary