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Biomedical subjects

J M Matloff

Publications and source records attributed to J M Matloff.

At least 127 records · Page 7Linked to original sources
PubMed1981

An appreciation of the new St. Jude valvular prosthesis.

Beginning in March, 1978, 88 patients have had cardiac valve replacements with St. Jude prostheses. There were 26 males and 62 females, aged 6 to 80 years (mean 60). Single valve replacement was done in 67. Double valve replacement was done in 21; 12 of them had two St. Jude valves and nine had a different second valve. There were 57 mitral and 43 aortic valves replaced. Thirty-six patients had concomitant aorta-coronary bypass, and six others had additional cardiac procedures. All patients have been followed for a total of 807 patient-months (mean 9 months). Seventy-nine have been receiving sodium warfarin and seven are not receiving anticoagulants. There has been one embolic episode. There are no valve failures to date. Early mortality is 2.3% and late mortality, 5.7%; no death was valve related. Fifty-three survivors have improved by two or more N.Y.H.A. classifications. Fifty-four valves studied postoperatively at rest, during pacing, and during isoproterenol infusion have demonstrated significantly better hemodynamic performance than have mitral porcine xenografts studied in an identical manner (p < 0.05). Phonocardiography, M-mode and two-dimensional echocardiography, and cinefluoroscopy, carried out in 18 patients, have proved to be reliable noninvasive techniques for long-term follow-up. This experience indicates that the St. Jude prosthesis offers an excellent and predictable alternative in the surgeon's decision-making concerning valve choices.

Adolescent↗
PubMed1979

Efficacy of systolic vs diastolic pulsation beyond severe coronary stenosis flow.

This paper describes the superiority of systolic pulsatile selective coronary perfusion as compared to diastolic pulsatile coronary perfusion in improving flow beyond ischemia-producing coronary artery obstructions in the working heart. The practical implications for use in coronary support perfusion systems are discussed.

Animals↗
PubMed1979

Distribution of oxygenated blood by transseptal left atrial cannulation during lung support in the open-chest model.

The hemodynamic characteristics and anatomic configuration of the aortic root determine the extent of coronary bed filling by the desaturated blood ejected by the left ventricle during conventional lung support with extracorporeal membrane oxygenation (ECMO), unless turbulence is created close to the coronary ostia by high-flow bypass ratios (greater than 80% of cardiac output) or ascending aorta cannulation. Using a total right heart bypass preparation, we studied the effect of returning blood transseptally into the left atrium upstream to the coronary arteries by means of a specially designed double-lumen cannula inserted via the jugular vein. Desaturated blood was used in six dogs ventilated with 100% oxygen (Group A), and oxygenated blood was used in 10 hypoxic dogs (Group B). We observed homogeneous mixing of oxygenated and desaturated blood at wide ranges of bypass flow ratios (20 to 80%) as determined downstream to the left atrium, i.e., left ventricle, coronary artery branch, root of the aorta, and descending thoracic aorta. Adequate coronary oxygenation (PO2 greater than or equal to 60 mm. Hg) was obtained with 40% of cardiac output oxygenation, a flow that could be met with a single superior vena cava (SVC) cannula through the major lumen of such a cannula. Total avoidance of high-pressure arterial cannulation and homogeneous distribution of oxygenated blood, regardless of the bypass flow ratio, by this technique are obvious advantages not available with conventional ECMO cannulations.

Animals↗
PubMed1978

Quantification of myocardial injury during coronary artery bypass graft.

Serial intraoperative myocardial-specific creatine-kinase (MB-CK) samples were obtained in 32 patients undergoing coronary artery bypass graft (CABG). Based upon their postoperative ECG and technetium pyrophosphate SCAN results, each patient was classified as either Group A (MI), B (normal), or C (equivocal). Peak MB-CK was reported for each group. The mean value for Group A (75 +/- 17 IU/L) is higher than for Group B (18 +/- 1 IU/L) or Group C (30 +/- IU/L). The concept of measuring and a formula for calculation of intraoperative myocardial injury are presented. The mean value for Group A (MI, 10,709 +/- 5885) is higher than either groups B (normal) or C (equivocal) by a test of proportionality (P < 0.001). Likewise, Group C (898 +/- 159) is higher than B (466 +/- 71) (P < 0.05). This index, while in need of further validation, corresponds closely to the clinical status of the 32 patients studied and should provide a means more refined than mortality or incidence of MI upon which to judge efficacy of any proposed means of operative myocardial preservation.

Aged↗
PubMed1978

Perioperative infarction: effects of cardiopulmonary bypass on collateral circulation in an acute canine model.

Significant intracoronary collateralization [circumflex (Cx) to anterior descending (AD)] can be established acutely by selective hypertensive perfusion of the circumflex (through left main) after acute occlusion of the AD in working canine hearts. Intracoronary collateral flow can be estimated by a collateral circulation index (CCI) = distal coronary diastolic pressure x 100/aortic diastolic pressure. The effects of 60 to 90 min of normothermic, total cardiopulmonary bypass (TCPBP) on such collaterals were evaluated in four dogs with CCI > 80%, and compared to six control dogs with CCI < 80% and without TCPBP. Three hours after AD ligation, control dogs had minimal myocardial injury despite significantly lower CCI. In contrast, the four study dogs placed on TCPBP experienced an abrupt fall of the CCI to 30% (P < 0.03), severe ischemia, and infarction in each; two became pump dependent. Thus, ventricular pressure work seems to be an important determinant of flow through collateral channels. These results suggest that preservation techniques for myocardium supplied by collaterals during coronary surgery may require considerations other than intermittent perfusion via existing coronary inflow.

Animals↗
PubMed1978

Aneurysm of the cardiac ventricle. Its management by medical and surgical intervention.

Ventricular aneurysm is usually a complication of acute transmural myocardial infarction. The development of cardiac aneurysm represents a process of continued thinning and fibrosis of the necrotic tissue of the ventricular wall. Survival allows the development of a solid fibrous scar which of itself does not affect global ventricular function substantially. Hence, ventricular aneurysms can be present for up to 18 years without production of serious symptoms. The cases were reviewed of 45 patients in whom aneurysmectomy and myocardial revascularization were carried out. Surgical mortality was low (6.6 percent, 30 days); survival one year after operation was 76 percent, but at three years had fallen to 47 percent. Cause of late death was dominantly cardiac. In 19 patients post-operative study was done; although graft patency was observed in 98 percent, substantive improvement in ventricular performance was seen in a minority of patients. The outcome in patients with ventricular aneurysm is primarily related to the status of the residual myocardium and to the status of the vessels which supply it. The mechanism of clinical improvement after aneurysmectomy has not been clarified. However, the long-term results appear to be similar to those in patients with extensive myocardial infarction.

Adolescent↗
PubMed1977

Coronary sinus blood flow and sampling for detection of unrecognized myocardial ischemia and injury.

Fifteen patients were studied to detect unrecognized intraoperative ischemia or necrosis in perioperative myocardial infarction (MI) associated with coronary bypass. Simultaneous arterial and coronary sinus blood samples were analyzed for lactate and both total and MB-CPK. Coronary sinus flow measurements were done coincident with sampling in seven patients. Five had perioperative MI diagnosed by positive pyrophosphate scan and electrocardiogram. Although normal initially (mean 19 +/- 5.0%), lactate extraction after thoracotomy, before aortic cross-clamping, became abnormal in 12 patients with more pronounced abnormality in those with perioperative MI (-19 +/- 9.0%). Net efflux of lactate was higher in perioperative MI (mean 0.6 +/- 0.2 vs 0.016 +/- 0.04 mM/L) than in non-MI patients. All patients had detectable total and MB-CPK (mean 295 and 31 IU/L, respectively) and all those with coronary disease had a positive arterial-coronary sinus gradient for MB-CPK (mean 9 IU/L). Perioperative MI patients had a higher gradient than non-MI patients (mean 25 vs 2 IU/L) and with one exception that gradient exceeded 5-7 IU/L. It is concluded that severe ischemia before aortic cross-clamping precedes perioperative MI and may contribute to release of CPK into coronary sinus blood. Improvement in the techniques of anesthesia and intraoperative myocardial preservation are suggested.

Adult↗
PubMed1977

Avulsion of a tricuspid valve leaflet during traction on an infected, entrapped endocardial pacemaker electrode. The role of electrode design.

Endocardial pacemaker electrodes rely in part upon endocardial fixation proximal to the electrode tip to prevent ejection of the tip from the ventricular apex. Fixation of these electrodes to the superior vena cava and tricuspid valve, in particular, has been reported. Infection of endocardial electrodes necessitates their removal. This report concerns avulsion of a tricuspid valve leaflet during traction on an infected electrode. With the availability of new methods of apical fixation, the utilization of electrode sheathing materials which discourage endocardial fixation would increase the safety of their removal under the circumstances reported herein.

Aged↗
PubMed1976

Bedside hemodynamic monitoring. Its value in the diagnosis of tamponade complicating cardiac surgery.

Cardiac tamponade may be a difficult clinical diagnosis in the early postoperative period in patients undergoing open-hear surgery, particularly when the anterior or lateral pericardium is left open. Bedside monitoring of intracardiac pressures and determination of a "pressure plateau" between right atrial, right ventricular diastolic, pulmonary arterial diastolic, and pulmonary capillary wedge pressures are useful in the early diagnosis of cardiac tamponade. The value of such hemodynamic monitoring in the diagnosis and treatment of cardiac tamponade in three patients with aorta-coronary artery bypass surgery in the early postoperative period is reported. Appropriate therapy, carried out on the basis of these studies, minimized the occurrence of further morbidity or possible death.

Adult↗
PubMed1975

Abnormal regional metabolism and mechanical function in patients with ischemic heart diseases: improvement after successful regional revascularization by aortocoronary bypass.

Left ventricular anterior wall metabolism was investigated concurrently with global myocardail metabolism by simultaneous preoperation sampling of anterior interventricular venous (AIV) and coronary sinus (CS) as well as arterial bloods in seven patients with severe obstructive lesions of the major coronary arteries, including left anterior descending. Postoperative study was performed two weeks to six months following successful aortocoronary artery bypass surgery. All grafts including the aorto-left anterior descending artery grafts were patent. Preoperatively in three of the seven patients, anterior wall lactate extraction (R%L) was negative at rest. The average R%L at rest (7 +/- 14%) was abnormal and was negative (-49 +/- 26%) at a maximum supraventricular pacing rate (MPR) of 137 +/- 4.6 beats/min. Postoperatively, not only was resting R%L (39 +/- 4;4%) normal but also it remained normal during atrial pacing (32 +/- 8.5%) even though the postoperative MPR (164 +/- 4.4 beats/min) was much higher than the preoperative MPR; Postoperatively AIV pO2 both at rest (21 +/- 1.1 mm Hg) and at MPR (22 +/- 1.3 mm Hg) and directly determined O2 saturations (resting: 34 +/- 3.0%; MPR:35 +/- 2.1%) tended to be higher than the preoperative values (AIV pO2, resting: 18 +/- 1.7; MPR: 19 +/- 1.7 mm Hg; AIV O2 saturation resting: 30 +/- 2.7; MPR: 33 +/- 3.3%), although only differences in pO2 were statistically significant. In five of the seven patients in whom the pre and postoperative left ventricular angiograms could be compared, systolic wall motion of the left ventricular anterior wall improved markedly postoperatively. Average global myocardial lactate extraction (G%L) preoperatively was normal (19 +/- 4.8%) at rest but was negative (-22 +/- 12%) at MPR. Postoperatively however, G%L both at rest (44 +/- 5.5%) and at MPR (34 +/- 7.9%) were normal. Coronary sinus pO2 and O2 saturation were also higher postoperatively compared to the preoperative values. Over-all left ventricular performance indicated by increase in ejection fraction also improved postoperatively. This improvement was not caused by increased coronary blood flow. Postoperative coronary sinus blood flow both at rest (114 +/- 19 ml/min) and at MPR (199 +/- 27 ml/min) however were less than the preoperative values (resting 136 +/- 24, MPR 261 +/- 40 ml/min), There was also no increase in global O2 delivery and O2 consumption despite higher heart rate and rate-pressure product achieved during postoperative pacing stress and the patients did not develop angina. These findings suggest that improved regional and global metabolism and mechanical functions observed postoperatively in these patients may be due to redistribution of blood flow to the ischemic and nonischemic myocardium following successful aortocoronary artery bypass surgery.

Adult↗
PubMed1975

Myocardial and plasma levels of adenosine 3':5'-cyclic phosphate. Studies in experimental myocardial ischemia.

Alterations in myocardial and plasma levels of adenosine 3':5'-cyclic phosphate (cyclic AMP) were studied following clamping of the aorta or coronary artery occlusion in 30 dogs. Plasma cyclic APM levels increased markedly after thoracotomy but returned to control levels two hours later. Complete arrest of aortic flow (clamping) induced a significant early increase in the myocardial cyclic AMP levels of all animals studied. No increase was noted following pretreatment with propranolol or sham-occlusion. After localized coronary occlusion, only modest and insignificant changes occurred in plasma cyclic AMP levels in anesthetized animals and also in conscious dogs. The present study suggests that adrenergically mediated changes in tissue cyclic AMP content are an early manifestation of both generalized and local myocardial ischemia, while the plasma cyclic AMP level is a relatively insensitive indicator of small coronary occlusions.

Animals↗
PubMed1975

The rationale for surgery in preinfarction angina.

Of 123 patients with identical clinical criteria for preinfarction angina, 35 were treated medically and 88 surgically in a nonrandomized manner. There was no statistical difference between these two therapeutic groups in regard to age range, average age, sex distribution, number and distribution of prior myocardial infarction, and duration of chronic and acute anginal symptoms. With medical therapy, 32 sustained a myocardial infarction, and 14 (40 per cent) of these died within 1 month of hospital admission. Thirteen of 21 survivors or 37 per cent of the original group are asmptomatic on continuing medical therapy an average of 15 months after discharge. The surgical patients were studied by catherization and anigiography and underwent an early operation. Eight (9.4 per cent) demonstrated evidence of postoperative infarction, and 3 (3.4 per cent) died after the operation. Seventy-one (84 per cent) are completely asymptomatic and 6 are less symptomatic an average of 17 months after the operation. Actuarial analysis of the follow-up data reveals that the initial significant difference in survival between the two groups is maintained through the first 36 months. On the basis of this experience, we suggest that surgical intervention is the therapy of choice in patients with preinfarction angina.

Adult↗