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Amelioration of ischemic left ventricular failure by intraaortic balloon counterpulsation in dogs
ABSTRACTS
6 l/2 years) after operation. Only 5 patients with unequivocal mitral rest,enosis were found; there was no history of rheumatic recrudescence, but in 1 patient progressive mitral valve calcification was noted. The more common causes for recurrent symptoms were residual mitral stenosis (16 patients), residual mitral stenosis with significant mitral
regurgitation (15 patients), and cardiovascular problems other than mitral valve disease (9 patients). It is concluded that although restenosis of the mit#ral valve does occur after a hemodynamically successful mitral commissurotomy, it is a relatively uncommon cause of postoperative sympt’omatic det,erioration.
Amelioration of lschemic Left Ventricular Failure by lntraaortic Balloon Counterpulsation in Dogs WILLIAM B. HOOD, Jr., MD, FACC/JULIO JOISON, MD/RAJ KUMAR, MD JOHN C. NORMAN, MD/JOHN V. TYBERG, PhD and CHARLES W. URSCHEL, MD Boston, Massachusetts
Effects of intraaortic balloon pump counterpulsation were studied in intact conscious dogs with left ventricular failure resulting from coronary ischemia. In 6 animals with previous left anterior descending coronary occlusion and healed anterior myocardial infarction, counterpulsation lowered left ventricular systolic pressure from 121 *- 2 to 112 * 3 mm Hg (SEM) and left vent,ricular end-diastolic pressure (LVEDP) from 15 -C 4 to 13 * 5 mm Hg, and raised aortic diastolic mean pressure from 92 + 3 to 104 rfl 1 mm Hg (P < 0.06, paired differences). Heart rate (88 f 6 beats/ min) and cardiac output (3.1 f 0.4 liters/min) were unaltered. Graded constriction of the circumflex vessel using an implanted balloon cuff coronary occluder resulted in stable but more severe left ventricular failure manifested by an increase in heart rate (+40 -C 4 beat,s/min) and rise
in end-diastolic pressure (+6 ir 4 mm Hg) . Aortic pressures and cardiac output did not change significantly. Now counterpulsation slowed heart rate by -28 + 3 beat&&, lowered LVEDP by -4 f 1 mm Hg, and increased stroke volume by +ll + 4 ml/beat (P < 0.05). Slowing of the heart rate with counterpulsation was gradual rather than abrupt, suggesting improved function of the ischemic left ventricle rather than operation of an autonomic reflex. Thus, with both chronic left ventricular failure due to single vessel occlusion, and more severe acute failure due to superimposed double vessel ischemia, counterpulsation enabled the left ventricle to pump the same ca.rdiac output at a lower end-diastolic pressure and, in the latter state, also at a reduced heart rate. Thus, counterpulsation effectively ameliorated the left ventricular failure resulting from experimental acute and chronic coronary insufficiency.
Closure of Ventricular Septal Defeot and Removal of Pulmonary Arterial Band. Results in Eleven Children CARL E. HUNT, MD/GUSTAVE FORMANEK, MD/ALDO R. CASTANEDA, MD, FACC and JAMES H. MOLLER, MD Minneapolis, Minnesota
Eleven children in whom pulmonary arterial banding was performed in infancy for large ventricular septa.1 defect have subsequently undergone operative closure of the defect and removal of the pulmonary arterial band. All patients have survived. Hemodynamic evaluation after corrective operation indicated successful closure of the ventricular septal defect in each patient. Pulmonary vascular resistance was near normal levels in 5 patients, moderately elevated in another 5 and markedly elevated in the remaining patient. In our 11 patients, the major complications of banding and subsequent operative repair were related to the development of obstructive lesions either in the right ventricular area or in the pulmonary artery. In 7 patients obstructive lesions developed, which were significant in two. In the latter 2 patients, 50 and 100 mm Hg pr~ure gradients,
VOLUME
25, JANUARY
1970
respectively, were present across the band site, despite widening of the pulmonary artery by a patch. In both patients reoperation on the band site was necessary. Other complications of banding were also demonstrated. In each of the 7 causes, thickening of the pulmonary valvular cusps with secondary pulmonary valvu1a.r steno&, although mild, has occurred. This complication may be related to the proximity of the band t.o the pulmonary valvular annulus. Acquired infundibulrsr pulmonary stenosis was also noted in 3 of the 7 cases, but in none was it significant. Despite the elevation of pulmonary resistance in some patients, and the acquired obstructive conditions, pulmonary arterial banding had beneficial effects in our patients and corrective operation was performed with low operative risk.
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6 l/2 years) after operation. Only 5 patients with unequivocal mitral rest,enosis were found; there was no history of rheumatic recrudescence, but in 1 patient progressive mitral valve calcification was noted. The more common causes for recurrent symptoms were residual mitral stenosis (16 patients), residual mitral stenosis with significant mitral
regurgitation (15 patients), and cardiovascular problems other than mitral valve disease (9 patients). It is concluded that although restenosis of the mit#ral valve does occur after a hemodynamically successful mitral commissurotomy, it is a relatively uncommon cause of postoperative sympt’omatic det,erioration.
Amelioration of lschemic Left Ventricular Failure by lntraaortic Balloon Counterpulsation in Dogs WILLIAM B. HOOD, Jr., MD, FACC/JULIO JOISON, MD/RAJ KUMAR, MD JOHN C. NORMAN, MD/JOHN V. TYBERG, PhD and CHARLES W. URSCHEL, MD Boston, Massachusetts
Effects of intraaortic balloon pump counterpulsation were studied in intact conscious dogs with left ventricular failure resulting from coronary ischemia. In 6 animals with previous left anterior descending coronary occlusion and healed anterior myocardial infarction, counterpulsation lowered left ventricular systolic pressure from 121 *- 2 to 112 * 3 mm Hg (SEM) and left vent,ricular end-diastolic pressure (LVEDP) from 15 -C 4 to 13 * 5 mm Hg, and raised aortic diastolic mean pressure from 92 + 3 to 104 rfl 1 mm Hg (P < 0.06, paired differences). Heart rate (88 f 6 beats/ min) and cardiac output (3.1 f 0.4 liters/min) were unaltered. Graded constriction of the circumflex vessel using an implanted balloon cuff coronary occluder resulted in stable but more severe left ventricular failure manifested by an increase in heart rate (+40 -C 4 beat,s/min) and rise
in end-diastolic pressure (+6 ir 4 mm Hg) . Aortic pressures and cardiac output did not change significantly. Now counterpulsation slowed heart rate by -28 + 3 beat&&, lowered LVEDP by -4 f 1 mm Hg, and increased stroke volume by +ll + 4 ml/beat (P < 0.05). Slowing of the heart rate with counterpulsation was gradual rather than abrupt, suggesting improved function of the ischemic left ventricle rather than operation of an autonomic reflex. Thus, with both chronic left ventricular failure due to single vessel occlusion, and more severe acute failure due to superimposed double vessel ischemia, counterpulsation enabled the left ventricle to pump the same ca.rdiac output at a lower end-diastolic pressure and, in the latter state, also at a reduced heart rate. Thus, counterpulsation effectively ameliorated the left ventricular failure resulting from experimental acute and chronic coronary insufficiency.
Closure of Ventricular Septal Defeot and Removal of Pulmonary Arterial Band. Results in Eleven Children CARL E. HUNT, MD/GUSTAVE FORMANEK, MD/ALDO R. CASTANEDA, MD, FACC and JAMES H. MOLLER, MD Minneapolis, Minnesota
Eleven children in whom pulmonary arterial banding was performed in infancy for large ventricular septa.1 defect have subsequently undergone operative closure of the defect and removal of the pulmonary arterial band. All patients have survived. Hemodynamic evaluation after corrective operation indicated successful closure of the ventricular septal defect in each patient. Pulmonary vascular resistance was near normal levels in 5 patients, moderately elevated in another 5 and markedly elevated in the remaining patient. In our 11 patients, the major complications of banding and subsequent operative repair were related to the development of obstructive lesions either in the right ventricular area or in the pulmonary artery. In 7 patients obstructive lesions developed, which were significant in two. In the latter 2 patients, 50 and 100 mm Hg pr~ure gradients,
VOLUME
25, JANUARY
1970
respectively, were present across the band site, despite widening of the pulmonary artery by a patch. In both patients reoperation on the band site was necessary. Other complications of banding were also demonstrated. In each of the 7 causes, thickening of the pulmonary valvular cusps with secondary pulmonary valvu1a.r steno&, although mild, has occurred. This complication may be related to the proximity of the band t.o the pulmonary valvular annulus. Acquired infundibulrsr pulmonary stenosis was also noted in 3 of the 7 cases, but in none was it significant. Despite the elevation of pulmonary resistance in some patients, and the acquired obstructive conditions, pulmonary arterial banding had beneficial effects in our patients and corrective operation was performed with low operative risk.
10.3