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Biomedical subjects

J C Broadbent

Publications and source records attributed to J C Broadbent.

18 recordsLinked to original sources
PubMed1984

Two decades of cardiac pacing at the Mayo Clinic (1961 through 1981).

Pacemaker procedures performed at the Mayo Clinic for the years 1961, 1971, and 1981 were reviewed to examine the changes that have occurred in a large pacemaker practice during the 2 decades since the advent of pacemaker therapy. Major changes in trends and practice have occurred; in addition to numerical growth, the indications for permanent pacing and the technologic alternatives available have expanded considerably. The increasing choices available today (in all areas of pacemaker practice) provide a challenging stimulus to physicians as they seek the best clinical options in patient care.

Cardiac Pacing, Artificial↗
PubMed1984

Pacemaker contact sensitivity.

In a patient who had 4 cardiac pacemakers implanted and removed, pruritus, redness, and swelling of the skin overlying the pacemaker developed at intervals of 6 weeks to 17 months after insertion. Patch testing showed a 2+ reaction to titanium. The positive result of this test, the titanium case of the generator, and the history of multiple local reactions around the generator site pointed toward contact sensitivity to the pacemaker. Although a review of the literature indicates that this problem is rare, it is of extreme importance to the patient with pacemaker contact dermatitis.

Adult↗
PubMed1983

Outcome of dual-chamber pacing for the pacemaker syndrome.

Symptomatic hypotension induced by VVI pacing (ventricular paced, ventricular inhibited) is characteristic of the pacemaker syndrome. Recent observations indicate that it is due to atrioventricular dyssynchrony. Since 1980, we have used the approach of converting the ventricular pacing to a dual-chamber pacing system in patients with this syndrome. The clinical course, hemodynamics, and response to dual-chamber pacing were evaluated in nine patients with the pacemaker syndrome whose ages ranged from 41 to 78 years. The indication for initial implantation of a pacemaker was symptomatic sinus node dysfunction in eight patients and intermittent Mobitz II block in one patient. One patient had a history of heart failure. The mean cardiothoracic ratio was 0.44. After initial implantation of a VVI pacemaker, all patients had syncope or near-syncope (mean duration, 10 months; mean frequency, one episode per month) despite normal pacemaker function. Eight of the nine patients had a symptomatic decrease in systolic blood pressure of greater than 20 mm Hg and ventriculoatrial conduction during VVI pacing. Dual-chamber pacing was instituted in all nine patients. This mode abolished pacing hypotension and its related symptoms. During a mean follow-up of 10 months, no patient has had recurrent syncopal or near-syncopal attacks related to pacemaker function. Dual-chamber pacing is an effective approach for treatment of the pacemaker syndrome.

Adult↗
PubMed1983

Reentrant tachycardia associated with atrial synchronous pacing. Report of a case with intact ventriculoatrial conduction.

Reentrant tachycardia occurred after implantation of an atrial synchronous ventricular-inhibited pacemaker in a patient with bradycardia caused by second-degree (Mobitz II) atrioventricular block. Despite the presence of antegrade atrioventricular block, intact ventriculoatrial conduction was present at a cycle length that exceeded the atrial refractory period of the pacemaker. Consequently, a reentrant or "endless-loop" tachycardia occurred. Application of a magnet terminated the tachycardia. Because the episodes were frequent and could not be prevented by medication, the pacemaker was reprogrammed to a ventricular-inhibited mode. All candidates for atrial synchronous pacing should undergo an appropriate electrophysiologic study preoperatively.

Atrioventricular Node↗
PubMed1981

Fabry cardiomyopathy in the female confirmed by endomyocardial biopsy.

A 58-year-old woman with cardiac enlargement and heart failure was a member of a family with Fabry disease. In this patient, endomyocardial biopsy permitted microscopic examination of the myocardium which revealed cellular abnormalities characteristic of Fabry cardiomyopathy. It is suggested that unfavorable lyonization of the mutant-bearing X chromosome accounted for the expression of this disorder in specific organs of a female patient.

Adolescent↗
PubMed1977

Quantitation of left ventricular myocardial fiber hypertrophy and interstitial tissue in human hearts with chronically increased volume and pressure overload.

Using new techniques, we quantitated left ventricular myocardial fiber hypertrophy and interstitial tissue in four groups of autopsied hearts free of coronary disease: 1) 22 normal hearts, 2) 20 hearts from patients with mitral incompetence (NYHA Class II-III) who died early after mitral valve replacement from causes other than cardiac failure, 3) 22 hearts from patients with mitral incompetence (NYHA Class III-IV) who died early after mitral valve replacement from cardiac failure with low cardiac output syndrome, and 4) 22 hearts from patients with hypertensive heart disease (NYHA Class II-III). Myocardial fiber hypertrophy was quantitated by measuring cross-sectional myocardial fiber diameter; the proportion of interstitial tissue was quantitated by using a computerized, high-resolution video image-digitizing system. Myocardial fiber average diameter in groups 2, 3 and 4 was significantly higher than group 1. The proportion of interstitial tissue was significantly increased in group 3. In chronic mitral incompetence an increase in left ventricular interstitial tissue may play a role in the development of severe cardiac failure.

Cardiomegaly↗
PubMed1975

Aortic and mitral valve replacement with cloth-covered Braunwald-Cutter prosthesis. A three-year follow-up.

From February, 1971, through February, 1974, heart valves of 510 patients were replaced with cloth-covered Braunwald-Cutter prostheses. The data indicate that cloth encapsulation of the prosthetic cage is associated with a reduction in thromboembolic complications, particularly for mitral valves. Cloth wear on the distal strut, however, is not prevented by use of a Silastic poppet and appears to be a typical finding in aortic valves recovered or inspected after 3 months. Excessive poppet wear has also been noted in the aortic position; poppet embolization has occurred on 2 occasions, and a third patient was found, at the time of reoperation for periprosthetic leak, to have opppet wear sufficient to permit embolization. Although there have been no reports of clinical malfunction of the mitral prosthesis at the time of this writing, further long-term observation of these patients appears warranted.

Adolescent↗