Biomedical subjects

Andrew H Goldstein

Publications and source records attributed to Andrew H Goldstein.

4 recordsLinked to original sources

PubMed2005

Partial support with a centrifugal left ventricular assist device reduces myocardial oxygen consumption in chronic, ischemic heart failure.

BACKGROUND: Left ventricular assist devices (LVAD) are increasingly used for heart failure (CHF); however, the level of optimal support has not been elucidated. We hypothesize that partial LVAD support in an ovine model of microinfarction-induced CHF significantly reduces left ventricular myocardial oxygen consumption (LVVO2). METHODS AND RESULTS: Microembolization of the circumflex coronary artery was used to induce CHF in 5 sheep (ejection fraction 28 +/- 2%). Four months later, animals underwent implantation of a centrifugal LVAD. LVAD flow was incrementally increased from 0% (baseline) to 25%, 50%, and 75% support of the LV. LVVO2 and stroke work (SW) were calculated at each increment. At baseline, LVVO2 (microL/100 g LV/beat) measured 43.2 +/- 3.4. LVVO2 decreased to 26.5 +/- 8.2,* 20.3 +/- 8.9,* and 12.6 +/- 6.3* at 25%, 50%, and 75% support (*P < .05). SW (mm Hg/mL) measured 1933.0 +/- 275.7 at baseline and decreased to 1588.0 +/- 204.1, 1181.0 +/- 157.2,* and 764.5 +/- 171.7* at 25%, 50%, and 75% support. Cardiac output, heart rate, and left main coronary artery blood flow were unaffected with partial support. CONCLUSION: Complete support with a centrifugal LVAD is not necessary for achieving significant reductions in LVVO2 . Partial support of as little as 25% significantly reduces LVVO2 in CHF through comparatively minor reductions in cardiac work. This is the first study to examine partial LVAD support in a CHF model.

Animals↗

PubMed2004

Selective microembolization of the circumflex coronary artery in an ovine model: Dilated, ischemic cardiomyopathy and left ventricular dysfunction.

BACKGROUND: Ventricular remodeling often occurs after myocardial infarction, yet the natural history remains unpredictable because of the chronicity of the process and therapeutic interventions involved. We induced cardiac dysfunction in an ovine model via selective microembolization of the circumflex coronary artery (LCx) to test the hypothesis that ventricular remodeling progresses following coronary microembolization for up to 24 months. Methods and results Sheep underwent weekly selective microembolization of the LCx until left ventricular ejection fraction stabilized <35% for 2 consecutive weeks. In a subgroup carried out to 4 months, the end-systolic pressure-volume relationship slope decreased from 2.3+/-0.6 (baseline) to 1.3+/-0.5 at month 4 (P<.05). In a second group, echocardiography at 24 months, the ejection fraction decreased from 51+/-3% (baseline) to 25+/-2% (month 5) (P<.05) and stabilized through month 24 (23+/-5%, P<.05), whereas left ventricular end-systolic area and left ventricular end-diastolic area increased by 222% and 98%, respectively, through month 24. CONCLUSIONS: Selective microembolization of the LCx induces left ventricular dysfunction followed by dilated, ischemic cardiomyopathy, which continues to progress for up to 2 years despite stabilization of left ventricular ejection fraction. This model of ventricular remodeling secondary to microinfarction may be a useful experimental platform for large animal heart failure investigations.

Animals↗

PubMed2002

Aortic arch replacement for recurrent cerebral embolization.

Replacement of the aortic arch for atheroma with cerebral embolization is in its infancy. The appropriateness of such intervention is controversial. Over a 10-month period, a 58-year-old woman suffered multiple debilitating cerebral vascular accidents manifested by motor, sensory, and memory deficits and documented by computed tomographic scanning and magnetic resonance imaging. Carotid and vertebral arteries were free of arteriosclerotic disease. Transesophageal echocardiography demonstrated two large atheromas with friable, pedunculated forms, one in the aortic arch and one in the very proximal descending thoracic aorta. Transcranial ultrasound revealed recurrent cerebral microembolic events. Cerebrovascular events continued, and the atheromas increased in size, despite treatment with Coumadin and aspirin. Under deep hypothermic arrest, the segment of the aortic arch harboring the atheroma was excised and replaced with a Dacron graft. Repeat transcranial ultrasound revealed cessation of embolic signals. All cerebrovascular events ceased. No further anticoagulation therapy was required. The patient has made substantial recovery from the preoperative deficits and continues to do well 1 year after aortic arch replacement. Resection of mobile aortic arch atheromas is likely to become increasingly important in the future as transesophageal echocardiography leads to their more common identification as a cause of cerebral ischemic events.

Aorta, Thoracic↗

PubMed2002

Short- and long-term results of open heart surgery in patients with abdominal solid organ transplant.

OBJECTIVES: Cardiac disease is a common cause of mortality and morbidity in patients with abdominal solid organ transplant. Improvement of the results of abdominal organ transplantation has contributed to an increasing pool of patients who require open heart surgery. We investigated short- and long-term results of open heart surgery in patients with functioning abdominal solid organ transplants. METHODS: We retrospectively examined 60 patients (52.5 years in average) undergoing coronary artery bypass grafting and/or valve surgery since July 1988 after abdominal organ transplantation. There were 22 females (37%). They consisted of 46 kidney, nine kidney-pancreas and five liver recipients. Cardiac surgery was performed 68.9 months after transplantation. Preoperative serum creatinine level was 2.1 mg/dl, and 11 patients (18%) had creatinine level more than 3.0 mg/dl. Eleven patients (18%) were operated upon on non-elective basis. Twelve patients (20%) were not given stress-dose steroids postoperatively. RESULTS: Three patients died early after surgery (5.0%). Twenty-six major complications were seen in 17 patients (28%), including deterioration of renal function in seven (three patients required temporary hemodialysis), three major infections, two bleeding complications, and two strokes. No graft loss was encountered. No differences were seen in mortality and morbidity between patients with or without stress-dose steroids. Multivariate analysis identified cardiopulmonary bypass time (P<0.05) as a risk factor for operative death, preoperative creatinine level (P<0.05), cardiopulmonary bypass time (P<0.05) and the amount of fresh frozen plasma used (P<0.05) for major complication, non-elective surgery (P<0.01) for deterioration of renal function. Thirteen patients died and five kidney allografts failed late after surgery. Three- and 5-year patient and graft survivals were 70.8 and 66.8, 84.5 and 84.5%, respectively. Multivariate regression analysis identified female gender (P<0.05), body mass index (P<0.001) and non-elective surgery (P<0.001) as risk factors for late death, and preoperative creatinine level (P<0.05) for late graft loss. CONCLUSIONS: Open heart surgery can be performed with acceptable short- and long-term results in patients with functioning abdominal transplants. Stress-dose steroid may be unnecessary in selected patients. Aggressive use of open heart surgery in this patient population to avoid non-elective surgery may further improve early and late surgical outcomes.

Adult↗