PubMed Health⌕ Search

Biomedical subjects

G M Lemole

Publications and source records attributed to G M Lemole.

At least 73 records · Page 4Linked to original sources

Charge levels in programmable pacemakers.

The method of calculation of charge in one series of programmable pacemakers is described. Accurate charge tables are constructed and examples of their use are given. With the tables the margin between the threshold and the pacemaker setting can be more precisely determined and consequently, at least in some cases, it can be reduced for greater pacemaker longevity.

Electric Conductivity↗

Successful management of Penicillium endocarditis.

Penicillium endocarditis involving an aortic valvular tissue prosthesis (Ionescu-Shiley) was successfully managed. This is the fourth reported case of Penicillium endocarditis, and the first survivor. A review of the literature shows that this fungus is ubiguitous though rarely pathogenic. The management of this rare type of infection is outlined.

Adult↗

Massive mitral regrgitation from chordal rupture and coronary artery disease.

The precise mechanism that causes spontaneous rupture of chordae tendineae remains unknown. That it may occur in patients with no disease other than underlying or associated coronary artery occlusion has not been previously reported. Six patients with chordal rupture were found among 600 patients who underwent operation for mitral regurgitation in a 6-year period. All 6 patients without exception underwent simultaneous mitral valve replacement and coronary revascularization. The salient clinical features of these patients are summarized, and 1 case is reported in detail.

Aged↗

Double-blind comparison of cefazolin and cephalothin in open-heart surgery.

Ninety-nine patients undergoing cardiac surgery were randomly assigned to treatment with cefazolin and cephalothin to compare the effectiveness of these cephalosporins in the prevention of postoperative infections. The incidence of infections was low with both antibiotics (cefazolin 2.1 percent, cephalothin 4.6 percent). Intraoperative serum cefazolin levels were more evenly distributed, whereas a wide dispersion of cephalothin levels was observed. There was no measurable antibiotic detected in cardiac tissue samples in the majority of the cases. Adverse reactions (skin rashes) occurred only in three patients, all receiving cephalothin. It is concluded that cefazolin is as safe and effective as cephalothin in the prevention of postoperative infection in patients undergoing open-heart surgery.

Adult↗

Recuperative potential of cardiac muscle following relief of pressure overload hypertrophy and right ventricular failure in the cat.

This study examined the recuperative potential of cat hearts subjected to experimental right ventricular pressure overload (for a 10- to 14-day period) which provoked hypertrophy with and without congestive heart failure. Five groups of cats were studied: normal controls; one group with 70% pulmonary artery constriction which produced right ventricular hypertrophy (RVH); one group with an 87% constriction which also produced right ventricular hypertrophy but with congestive heart failure (CHF); and two groups which had been similarly subjected to pressure overload but which had been allowed a recovery period of 30 days after relief of the pressure overload. Both the 70% and 87% pulmonic constrictions were associated with extensive right ventricular hypertrophy, depression of myocardial contractile function, and severe redlction of cardiac norepinephrine stores (normal, 1.42 mug/g: RVH, 0.11 mug/g; CHF, 0.01 mug/g). After a 30-day period of relief from the pulmonic constriction normal hemodynamic function returned. In cats in which RVH had been relieved, right ventricular weight and contractile function were normal but catecholamine depletion persisted. Cats with relieved CHF showed depressed contractile function and depleted myocardial norepinephrine, and the right ventricular weight did not return to normal. Cardiac muscle of all pressure-overloaded nonrelieved hearts showed depressed velocity of shortening and depressed ability to sustain load. Cats with RVH alone regained normal muscle shortening velocity and load-bearing ability after relief. However, cardiac muscle from the CHF-relieved group recovered only unloaded shortening velocity while the ability to sustain load remained depressed. We conclude that the recuperative potential of myocardium damaged by pressure overload is adequate provided congestive heart failure has not occurred. Heart failure produces a persistent reduction in force-generating ability of the myocardium. Hypertrophy due to pressure overload, with or without CHF, leads to cardiac catecholamine depletion which is not readily reversed by relief of the overload.

Animals↗

Successful correction of all mechanical complications of ischemic heart disease in the same patient.

Extensive surgery for all of the mechanical complications of ischemic heart disease is feasible with early diagnosis, catheterization, and aggressive medical and surgical therapy. A patient is report who, after recovering from cardiogenic shock, required a coronary bypass, closure of ventricular septal defects, mitral valve replacement, aneurysmectomy, and temporary pacemaker wires. The outcome was successful.

Aged↗

Retrograde coronary capillary perfusion for prevention and reversal of cardiogenic shock in experimental myocardial infarction.

The coronary sinus and coronary veins offer an access route for delivery of increased oxygen to ischemic myocardium surrounding the central dead zone of heart muscle in cardiogenic shock due to myocardial infarction. This investigation was conducted to determine if transvenous retrograde coronary capillary perfusion with oxygenated blood would prevent and reverse cardiogenic shock in experimental myocardial infarction produced by acute ligation of the circumflex and anterior descending left coronary artery in dogs. Cardiac output and systemic blood pressure were maintained near control values for up to 30 minutes when total left coronary ligation was accompanied by coronary retroperfusion. Conversely, both cariac output and systemic blood pressure fell to severe cardiogenic shocks levels within 2 minutes of total left cardiogenic shock levels within 2 minutes of total left coronary artery occlusion without retrograde flow or when retrograde flow was terminated 5 to 30 minutes following simultaneous coronary ligation and institution of retrograde flow.

Animals↗

Subaortic stenosis caused by two discrete membranes.

A case of subaortic stenosis caused by two discrete membranes is presented. Following demonstration of the two distinct sites of obstruction by intraventricular pressure gradients and angiocardiogram, the two membranes were excised through a transaortic approach. The importance of being aware of the occurrence of this rare anomaly is stressed, and its surgical implications are discussed.

Angiocardiography↗

Late thrombosis of the aortic Bjork-Shiley prosthesis. Its clinical recognition and management.

Seven cases of massive thrombosis of an aortic Bjork-Shiley prosthesis were encountered among 433 valvular implants. Four patients died before treatment could be instituted, and three underwent repeat surgery successfully. Anticoagulation therapy was probably well maintained in four, and poorly maintained in three patients. These cases illustrated the need for a high index of suspicion and prompt recognition of this complication in patients with Bjork-Shiley prostheses. The diagnosis of massive thrombosis should be suspected with the rapid onset of (1) signs of congestive heart failure, (2) absence or attenuation of valvular clicks, (3) aortic regurgitation, or (4) hemolytic anemia. Salvage of these patients requires emergency replacement of the thrombosed prosthesis or removal of the thrombus.

Aged↗

A method of preventing air embolus in open-heart surgery.

Intraoperative air embolus following cardiac surgery poses a serious problem. Many maneuvers have been suggested in an attempt to minimize its occurrence. Partial aortic clamping, creating a cupola which collects this air, is combined with aortic venting. The use of this simple technique is described as an alternative and easily applicable trouble-free method.

Cardiac Surgical Procedures↗

Improved technique of double valve replacement.

Double valve replacement in the aortic and mitral positions continues to present significant morbidity and mortality rates. At present, the replacement operation is performed with the use of either ischemic arrest or coronary perfusion. In this report, we describe a new method whereby the anterior portion of the mitral valve and the aortic valve are replaced with the aid of ischemic arrest, and then the posterior portion of the mitral valve and left atrium are repaired while the myocardium is being perfused through the native ostium. This technique has been used in 33 patients with one operative death in the last 4 years and has significantly reduced our mortality rate in this time.

Adolescent↗