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Biomedical subjects

D M Behrendt

Publications and source records attributed to D M Behrendt.

At least 73 records · Page 4Linked to original sources
PubMed1981

An operation for the hypoplastic left heart syndrome: preliminary report.

A successful first-stage operation for physiological correction of hypoplastic left heart syndrome is reported. This consists of creating a proximal communication between the pulmonary artery and the aorta while perfusing the lungs through a 3 mm orifice in a flap of pulmonary artery wall. The flap is turned in to partition the main pulmonary artery. We believe this operation has more potential for subsequent correction using the Fontan approach than previously reported first-stage procedures. Thus, further trial is indicated in selected patients.

Aorta, Thoracic↗
PubMed1981

Surgical management of neonates with complex preductal aortic coarctation.

Neonates having repair of aortic coarctation commonly have associated ventricular septal defect and patent ductus arteriosus. Prostaglandin E1 is used to dilate the ductus and improve the patient's preoperative condition. An operative technique that maintains ductal patency until the final stages of anastomosis is presented. We believe it has contributed to our present improved results.

Aorta↗
PubMed1981

Electrophysiologic delineation of the intraventricular His bundle in two patients with endocardial cushion type of ventricular septal defect.

Two patients who had an endocardial cushion type of ventricular septal defect underwent electrophysiologic studies for detection of specialized conduction tissue during operative repair. In one patient, with an inferior leftward frontal plane QRS axis on the ECG, we recorded an intraventricular His bundle electrograms from both the anterosuperior and posteroinferior margins of the defect, suggesting dual atrioventricular conduction tracts (branching intraventricular His bundle). These anatomic and electrophysiologic findings may account for the more normally oriented QRS frontal plane axis on the surface ECG of both of these patients and support the hypothesis that the changes observed on the ECGs of patients with the various forms of endocardial cushion defect can be explained by alterations in the anatomic configuration of the specialized atrioventricular conduction tissue.

Bundle of His↗
PubMed1980

Cardiovascular status after repair by Fontan procedure.

Patients surviving a Fontan operation experience dramatic symptomatic improvement, but concern remains about the long-term results of this operation. The clinical course and postoperative hemodynamic findings in 5 long-term survivors of the Fontan procedure from our institution are presented. Attention is drawn to 3 patients who required reoperation: 1 immediately for residual mild pulmonary stenosis, 1 for late onset complete heart block, and 1 for conduit valve stenosis. Review of our patients and those described in the literature reveals that all have ascites and pleural effusions as a results of high venous pressures but that this is usually a temporary problem. Late onset of obstruction to right atrial emptying has been reported in several patients in addition to ours. This raises serious concerns about the long-term fate of cloth conduits and porcine valves in this application. Although normal sinus rhythm has been thought to be essential for adequate pulmonary perfusion in these patients, it is interesting that several patients have tolerated atrial tachyarrhythmias, junctional rhythms, and even complete heart block without serious ill effects. We conclude that the Fontan procedure is extremely effective in relieving symptoms at an operative risk that is now acceptable, but these patients require very careful long-term follow-up because they are subject to a number of long-term complications.

Adolescent↗
PubMed1980

Open-heart surgery in the first week of life.

The high mortality of open-heart operations in infants with congenital heart disease has traditionally led to deferral of definitive operation and to use of medical therapy or palliative procedures. The technique of deep hypothermia with circulatory arrest and advances in intensive care have made early repair possible. Since 1973, we have repaired life-threatening but correctable lesions in 11 infants in the first week of life. There are 7 survivors. Four patients had total anomalous pulmonary venous drainage, 2 had truncus arteriosus (1 with aortic arch interruption), and 1 each had pulmonary atresia and intact ventricular septum, critical pulmonary stenosis and intact ventricular septum, D-transposition of the great vessels, tetralogy of Fallot, and left ventricular-aortic tunnel. Postoperative hypoglycemia (less than 50 mg per 100 ml) developed in 4 patients and hypocalcemia (less than 7 mg per 100 ml), in 5. These problems responded appropriately to replacement therapy. Three of the survivors experienced renal failure, a complication subsequently prevented by use of mild hemodilution perfusion. Two patients had major bleeding, which now is prevented by finer suturing and administration of vitamin K and platelets. One infant, moribund with pH of 6.8 when brought to operation, sustained a cardiac arrest with subsequent brain damage. We conclude that newborns with life-threatening malformations can undergo successful repair. Attention must be paid to their unique metabolic demands, and surgical technique must be meticulous. Early operation before clinical deterioration is essential.

Follow-Up Studies↗
PubMed1980

Oculoplethysmography in diagnosing obstruction of the superior vena cava.

Preoperative evaluation of a patient with symptomatic obstruction of the superior vena cava secondary to sclerosing mediastinitis demonstrated abnormal plethysmographic findings in the central venous and carotid systems. Arteriography confirmed diminished blood flow to the arms and cerebral vessels. Following in continuity saphenous vein conduits to the jugular system, he improved symptomatically and postoperative oculoplethysmography showed a return to normal of his pulse wave form and absent pulse delay in the venous and arterial systems.

Adult↗
PubMed1980

Comparison of the effect of blood cardioplegia to crystalloid cardioplegia on myocardial contractility in man.

The myocardial protection achieved by blood cardioplegia was compared to that achieved by crystalloid cardioplegia in a randomized prospective series of patients having coronary bypass operations. Group BCP (n = 15) was protected with 10 degrees C blood containing potassium, 30 mEq/L; Group KCP (n = 9) by an electrolyte solution at 4 degrees C with mannitol, 25 gm/L, and potassium, 26 mEq/L, and group MgKCP (n = 9) by an electrolyte solution at 4 degrees C containing magnesium, 30 Meq/L, and potassium, 19.6 mEq/L. The three groups were comparable in regard to age, sex, preoperative left ventricular function, symptoms, propranolol use, previous myocardial infarction, number of vessels bypassed, and duration of ischemic arrest. In each patient cardiac output, left ventricular end-diastolic pressure (LVEDP), and maximum contractile element velocity (Vpm) were recorded before and after the ischemic period. All operations were performed in an identical manner with one continuous period of aortic cross-clamping averaging 52.9 minutes. No significant alterations in myocardial function were observed after ischemia within the BCP or KCP groups. However, patients receiving MgKCP had significant (p = 0.02) depression in Vpm from 2.86 +/- 7.8 to 2.04 +/- 3.6 second-1 and increase (p < 0.05) in LVEDP from 9.4 +/- 2.2 to 13.4 +/- 5.2 mm Hg. Analysis of variance between groups showed that Vpm decreased significantly (p < 0.05) and LVEDP increased significantly (p < 0.05) in the MgKCP group by comparison to the BCP group. Patients receiving BCP experienced spontaneous defibrillation more frequently (p < 0.02) and received nitroprusside postoperatively more often (p < 0.05) than patients in the other two groups. From these results we conclude that blood cardioplegia provides excellent protection during myocardial ischemia, probably better than one of the two crystalloid solutions tested but no better than the other crystalloid solution. Because the three solutions differed from one another in several respects, no conclusion can be reached about the efficacy of any one ingredient.

Adult↗
PubMed1979

Effects of methylprednisolone in cardioplegic solution during coronary bypass grafting.

The effects of adding 500 mg. of methylprednisolone to each liter of cardioplegic solution were studied in patients undergoing coronary artery bypass grafts. Patients were randomly assigned to control (12 patients) or steroid-treated groups (10 patients). The cardioplegic solution was identical in the two groups except for the added methylprednisolone. Contractile element velocity (VCE and left ventricular end-diastolic pressure (LVEDP) were recorded immediately before and after perfusion in the operating room. There were no differences between the two groups with respect to these two variables or the postoperative courses. Thus this study fails to demonstrate a beneficial effect of methylprednisolone when added to cardioplegic solutions.

Coronary Artery Bypass↗
PubMed1978

Effects of cardioplegic solution on human contractile element velocity.

A technique for measuring the maximum contractile element velocity (Vpm) of the myocardium was developed, verified, and employed in patients to allow accurate intraoperative assessment of the adequacy of myocardial protection. Four groups of patients were studied. Ten patients had coronary artery bypass grafts (CABG) with cardioplegia; 13 had CABG with coronary perfusion, ventricular fibrillation at 28 degrees C, and aortic clamping for distal anastamoses; 6 had aortic valve replacement (AVR) with cardioplegia; and 7 had AVR with coronary perfusion to the beating heart. For cardioplegia, a solution of 5% dextrose in 0.2% saline at 4 degrees C with 25 mEq of potassium chloride and 12.5 gm of mannitol was infused initially, followed by 500 ml every 30 minutes. Clinically all patients did well, and there were no deaths. Patients having CABG with intermittent coronary perfusion during ventricular fibrillation had significant (p less than 0.01) depression of Vpm from 38.3 to 30.8 sec-1 while Vpm in patients having CABG with cardioplegia was unchanged. Patients having AVR with continuous coronary perfusion or with cardioplegia (average anoxia time, 70.4 minutes) had no significant change in Vpm. We conclude that this cardioplegic solution provided adequate protection of myocardial function for up to 105 minutes of continuous aortic clamping in humans. The depression in Vpm observed following CABG with intermittent coronary perfusion is consistent with previous suggestions that this combination is detrimental because of maldistribution of coronary blood flow during ventricular fibrillation.

Aortic Valve↗
PubMed1978

Myocardial revascularization in patients receiving long-term propranolol therapy.

Twenty-seven patients receiving long-term propranolol therapy underwent myocardial revascularization to relieve stable or unstable angina. The patients were randomly divided into two groups, one (Group 1) in which propranolol was discontinued 48 hours prior to operation and one (Group 2) in which patients received a final dose of propranolol 1 to 2 hours prior to operation. Several physiological variables were compared, and there was no statistically significant difference between the groups except for a slower pulse rate in Group 2 patients. Although the patients in Group 1 showed a greater frequency of hypertension before bypass, the incidence of postoperative complications and perioperative myocardial infarction was the same for both groups. The findings of this study indicate that myocardial revascularization is safe even if propranolol is administered up to 1 or 2 hours before operation.

Adult↗
PubMed1978

Management of unusual traumatic ruptures of the aorta.

Blunt injuries to the ascending aorta and branches of the aortic arch are unusual but must be considered in any victim of a high speed decelerating injury. Because there are no characteristic clinical or roentgenographic findings, aortography is the only definitive method of establishing the diagnosis. Aortography should therefore, be performed upon any patient who has had a high speed decelerating injury, regardless of the clinical or the roentgenographic findings. An early operation will prevent exsanguination.

Adolescent↗
PubMed1978

Effect of temperature of cardioplegic solution.

This study tests the hypothesis that the efficacy of cardioplegic solution depends upon its chemical constituents rather than on its temperature alone. A standard preparation of right heart bypass in the dog was utilized. Left ventricular function curves were inscribed before and after 1 hour of aortic cross-clamping. No deterioration in function was observed in nonischemic control hearts or in hearts protected with cardioplegic solution consisting of potassium chloride (25 mEq. per liter) and mannitol (12.5 Gm. per liter in 5 percent dextrose and 0.2 percent saline at either 4 degrees C or 28 degrees C. Severe myocardial depression was observed in hearts rendered ischemic for 1 hour at 28 degrees C. without protection and also in hearts perfused with 5 percent dextrose and 0.2 percent saline at 28 degrees C. without the potassium chloride and mannitol. The evidence from this study indicates that cardioplegic solution exerts a protective effect beyond that which is afforded by hypothermia.

Animals↗