John C. Hutchinson

Noninvasive diagnosis of a false left ventricular aneurysm with radioisotope gated cardiac blood pool imaging: Differentiation from true aneurysm

Unlike the true left ventricular aneurysm, false aneurysms have recently been shown to be subject to late rupture. Rarely diagnosed before surgery or autopsy, the false aneurysm has never been identified by noninvasive techniques. We report the first such noninvasive diagnosis employing radioisotope gated cardiac blood pool imaging. Due to the unique and possibly life-threatening clinical course and potential for surgical cure of false left ventricular aneurysm, early noninvasive diagnosis by imaging techniques may be critical. The methods shown here are generally applicable, becoming widely available and may help in evaluation of false left ventricular aneurysm as a cause of sudden death.

Valve Replacement for Bacterial and Fungal Endocarditis A Comparative Study

Twenty-eight of 143 patients treated for infective endocarditis had replacement of one or more cardiac valves within six months after the diagnosis was made. Twenty-two patients (16%) with bacterial endocarditis had operation, and six died in hospital. All six patients with fungal endocarditis required vale replacement, and one died in hospital. Uncontrolled or progressive heart failure was the indication for operation in all patients with bacterial endocarditis. When severe heart failure was present, 5 of 11 patients with bacterial endocarditis died in hospital, and only 1 of 3 patients with associated bacteremia survived. If blood cultures were sterile, the duration of preoperative antibiotic therapy did not correlate with hospital survival. None of the patients with bacterial endocarditis developed prosthetic infections, but two developed paravalvular leak.Massive emboli or persistent mycotic septicemia were the indications for valve replacement in patients with fungal endocarditis. Viable organisms were cultured from the excised valves in all of these patients in spite of preoperative amphotericin B for 30 to 140 days and negative blood cultures. Excision of the infected valve cured the infection in all patients.Five patients died 6 weeks to 36 months after operation. At the present time 16 patients remain alive 14 to 47 months after operation. Six of nine drug addicts are alive 15 to 27 months postoperatively.

Open mitral valvulotomy.

Abstract A five-year experience with routine open visualization of the mitral valve in 95 patients with mitral stenosis resulted in salvage of 53 valves and replacement of 42. The subvalvular structures were often thickened and fused, and meticulous dissection was necessary to produce adequate mobilization of the valve leaflets. An operative mortality of 1 death among the 53 patients undergoing commissurotomy attests to the safety of the procedure, but immediate functional results were not significantly better than with the closed method. Sufficient mobilization to produce a wide-open orifice in the relaxed state may be an important factor in the functional result.

Occluder Disruption of Wada-Cutter Valve Prosthesis

Total detachment and embolization of the hinged, tilting occluder of the Wada-Cutter prosthetic heart valve was the proved cause of death in 2 of 25 patients who had these devices implanted at the University of California, San Francisco, Medical Center in 1969-70. In addition, there were 8 late deaths without postmortem examination, 2 of which were sudden and 4 of which followed rapidly progressive congestive heart failure over a period of hours to days. Prosthetic malfunction appears to be a possible mechanism of death in the majority of these patients. The 2 additional late deaths were unrelated to valve malfunction. Regurgitant murmurs have been identified during follow-up examination in 17 patients. Two patients had prosthetic replacement for hemodynamically significant leaks through the valve mechanism and were found to have no perivalvular leak. Six additional patients had prophylactic replacement of the Wada-Cutter valve. Measurements on 7 available occluders that were removed showed variable degrees of material movement at the hinge. This experience has caused us to recommend elective replacement of remaining Wada-Cutter valves.

Control of the hazards of cardiac valve replacement

Abstract Forty-seven consecutive patients underwent operations for valve replacement during a nine month period, with one hospital death. Thirteen patients were men and thirty-four were women. The patients ranged in age from twenty to sixty-six and nineteen of them were more than fifty years old. Sixty valves were replaced with Starr-Edwards prostheses and ten valvuloplasties were performed. Particular care must be taken to avoid the potential hazards of cardiac valve replacement including ischemic damage to the diseased myocardium, air embolization, arrhythmias caused by cation shifts, and depressed cardiac output after operation.

The Effects of FM and TV Broadcast Stations upon Cardiac Pacemakers

Since about 1965 numerous discussions of pacemaker EMI problems have appeared in the literature. An extensive study in vitro of the effects of electromagnetic fields upon pacemaker performance has been conducted by the Society of Automotive Engineers. They reported that pacemakers were affected by VHF field intensities in the range of one to five volts per meter. A study of the effects of pulsed radio frequency fields upon the performance of pacemakers implanted in dogs has been made by the Air Force. They found that one type of implanted pacemaker could be stopped by a UHF field intensity of three to five volts per meter. Very little data on the effects of FM and TV signals has appeared in the literature. In order to predict the possible effects of the New Sutro Tower upon pacemaker performance at the University of California San Francisco, we conducted in vitro pacemaker tests near the FM and TV transmitter sites on San Bruno mountain. We found that one type of external pacemaker stopped in an area where the maximum average field intensity was 0.63 volt per meter. The other pacemakers functioned normally in an area where the highest measured average field intensity was one volt per meter. Most of them functioned erratically or even stopped under certain conditions in an area where the highest measured average field intensity was 2.8 volts per meter. Some of the test conditions (such as the substitution of a dipole antenna for the catheter) were more severe than would be encountered during normal operation. Our Office of Environmental Health and Safety has established a tentative standard which requires that the field intensity within this hospital must not exceed either 1 volt per meter average or 1.5 volt per meter peak.