Arthur B. Simon

Coarctation of the Aorta Longitudinal Assessment of Operated Patients

One hundred and ninety patients over the age of two operated upon for coarctation of the aorta from 1957 to 1972 at one institution were followed for one to 15.5 years (mean, 6.6 years). There were eleven cardiovascular deaths in the follow-up period. The mean age at death was 32.5 years. Two-thirds of the patients had an associated cardiovascular anomaly; 74 had coexistent aortic valve disease, and 19 had mitral stenosis or insufficiency. Five patients had a significant central nervous system event in the late postoperative period. Left ventricular hypertrophy by electrocardiogram was noted in 45, and 72 had radiographic left ventricular hypertrophy. A significant persistent or residual hemodynamic abnormality, either congenital heart disease, residual coarctation or persistent diastolic hypertension, could account for the residual electrocardiographic or radiographic abnormality. The data indicate that this population requires continuing care despite correction of the coarctation.

Symptomatic Bradyarrhythmias in the Adult: Natural History Following Ventricular Pacemaker Implantation

The preimplantation arrhythmias, coexistent medical conditions, the causes of death, and survival course are described for 399 patients who received their initial ventricular pacemaker implantation for a bradyarrhythmia (AV block, sinus node disease, and hypersensitive carotid sinus syndrome) at the University of Michigan from 1961 to 1979. Factors which correlated with a poor survival are elucidated. Survival for those with sinus node disease was virtually identical to those with AV block, with only 63% surviving over five years. Advanced age and congestive heart failure prior to implantation, and underlying ischemic or hypertensive heart disease portended a poorer survival in both groups. Patients with hypersensitive carotid sinus syndrome had a distinctly better prognosis—no deaths occurred until the eighth year after pacing. Patients with no underlying heart disease and those with valvular disease did remarkably better than those with an ischemic or myopathic etiology. Apparent progression or complications of the underlying heart disease was the major cause of mortality. Sudden death, congestive heart failure, myocardial infarction, and major arrhythmias were the causes of death in 48% of those who died. Implications of improved pacing modalities an late complications and death are discussed. (PACE, Vol. 5, May‐June, 1982)

Symptomatic Sinus Node Disease: Natural History After Permanent Ventricular Pacing*

Fifty‐nine patients between the ages of 13 and 88 with sinus node disease, who received a permanent ventricular pacemaker between 1965 and 1976 at one institution, were followed to determine the natural history of the disorder after permanent pacing. Nineteen had ischemic heart disease, six had primary myocardial disease, and eight valvular heart disease. In 26, no etiology for the arrhythmia was apparent. The one‐ and five‐year survival was 85.5% and 73.1%, respectively. Patients with underlying heart disease had a significantly poorer survival when compared to those without (58% versus 94% at 36 months), and all but 3 of 13 deaths in the first 36 months were in those with ischemic heart disease. There was a distinct trend toward poor survival in those with heart failure prior to pacemaker implant and those over age 65. Patients with sinus bradycardia alone did best (91% survival three years after implant), while those with bradycardia‐tachycardia syndrome and those with sinoatrial arrest alone did distinctly worse (76% and 65% survival at three years, respectively). Twelve of 18 deaths were due to progression of underlying heart disease. The long‐term prognosis with symptomatic sinus node disease can be predicted in part by (1) etiology of the underlying heart disease, (2) pre‐implant arrhythmia, and (3) ventricular function prior to implant. (PACE, Vol. 2, May‐June, 1979)

Ventricular Pacing in Children

Ventricular pacing in children. Ventricular pacing was performed in forty‐one children ranging from one day to twenty years of age (median age = 10). Weight of the recipient at implant ranged from 2 kg. to 86 kg. Indications included presyncope, syncope, dyspnea on exertion, congestive heart failure, postoperative infra‐Hisian heart block, and inadequate cardiac rate during pharmacotherapy. Four patients died during follow‐up, but no deaths were attributable to pacemaker management. In contrast, 66% of the patients required more than one pacemaker related‐operative procedure, and 43% of leads implanted failed by 48 hours. Indications for permanent cardiac pacing in this population at this time are symptomatic congenital AV block, symptomatic sinus node disease, and AV block in the postoperative period. Technological developments which might reduce complications seen in this population and electrophysiologic techniques which may better define indications for pacing in children are also reviewed.

Candida Myocarditis Without Valvulitis

Thirty-one patients with systemic candidiasis at postmortem examination were found to have Candida involvement of the myocardium without valvulitis. Retrospective examination of their clinical course demonstrated that a new conduction disturbance was seen in 10, supraventricular arrhythmias in 5,QRS changes mimicking myocardial infarction in 3, and pronounced T wave changes in 13. Hypotension or shock was seen in 13 patients and could not be explained by coexistent bacteremia or blood loss in 8. One patient died suddenly. Of 19 patients with systemic candidiasis without myocardial invasion, 4 had minor T wave changes and one had a supraventricular arrhythmia. Candida invasion of the heart significantly complicates the clinical course in systemic candidiasis and should be suspected when a young person without preexistent heart disease has cultures positive for a Candida organism, a significant arrhythmia, conduction distrubance or other dramatic QRS change. The effect of therapy on Candida invasion of the heart is unknown.

Atrioventricular block: Natural history after permanent ventricular pacing

The preimplantation status, postimplantation morbidity and causes of late mortality were summarized for 246 patients who underwent pacing for atrioventricular (A-V) block at the University of Michigan for the 14 years from 1961 to 1974. The survival rate at 1, 5 and 10 years was 88, 61 and 49 percent, respectively. Risk of death was greatest among patients with antecedent ischemic or hypertensive heart disease or congestive heart failure in the period before pacemaker implantation, patients older than 74 years at initial implantation and those receiving a pacemaker before 1965. Forty-two percent of the 109 deaths were related to apparent progression of underlying cardiac disease. Pacing system malfunction was a contributing documented cause of only 3 deaths. Even with permanent pacemaker implantation, patients with A-V block have a higher age-specific mortality rate than the general U.S. population. Survival improved steadily over the period of study. This change is attributed to apparent improvements in treatment of cardiovascular disease including more effective treatment of congestive heart failure and valve replacement for selected patients as well as elimination of immediate postoperative mortality.

Long-term intravenous infusion of antiarrhythmic drugs using a totally implanted drug delivery system

In vitro and in vivo testing was performed to establish the feasibility of a totally implantable pump system to deliver antiarrhythmic agents. In vitro flow characteristics suggested predictable day to day delivery with acceptably small variations in flow with changes in reservoir volume or temperature. During 3 months of in vitro testing, procainamide and bretylium were found suitable for long-term delivery. Delivery of lidocaine was limited by high viscosity and corrosion of steel elements within the pump. The pump was implanted in a subcutaneous pocket in four dogs. Procainamide (0.5 g/ml), delivered at 4 ml/day (70 mg/kg body weight per day), provided a mean steady state drug concentration of 5.3 micrograms/ml. Bretylium (50 mg/ml), delivered at 8 ml/day (13 mg/kg per day), provided a steady state concentration of 0.8 micrograms/ml (range 0.4 to 1.4). Long-term intravenous administration of therapeutic doses of bretylium and procainamide with this delivery system has been demonstrated in dogs and appears to be feasible in human subjects.

Suicide Attempt by Pacemaker System Abuse: A Case Report with Comments on the Psychological Adaptation of Pacemaker Patients

Thirty patients seJected at random from a pocemaker clinic were inter‐viewed to gain an understanding of how psychological symptoms in these patients related to their cardiac condition. In 20% veiled depresslon or even a wish to die was elicited. loking, fantasies, and denial were common psychological mechanisms used to adapt to their illness and the pacemaker itself. A dramatic example of attempted suicide in which the patient tried to cut the subcutaneously implanted pacemaker leads is presented and illustrated.

The demography, career pattern, and motivation of locum tenens physicians in the United States.

EXECUTIVE SUMMARY The objective of this study was to provide a profile of locum tenens providers and their motivation for choosing this practice pattern. The research design used was a cross‐sectional mailed survey questionnaire. Participants included the 1,662 physicians who accepted at least one locum tenens assignment in 2001 from one physician staffing service. They were asked to complete a 50‐element questionnaire; 776 (47 percent) responded. The average age of respondents was 53.0 years. Men represented 70.3 percent of the sample and were significantly older (56.3 years) than women providers who responded (45.3 years). One‐third considered a locum tenens practice pattern permanent. Primary care locums were younger than specialists and subspecialists. Female providers were disproportionately practicing in primary care specialties (43.9 percent); 64 percent used locum income as their sole source of support and were frequently (31 percent) motivated by a need for a flexible work schedule. Male locum physicians were weighted toward the subspecialties and were motivated mostly (62 percent) by a desire to continue to practice part time. They used locum income as a secondary means of support (33 percent) or to augment pension and retirement resources (38 percent). A physician workforce from most major specialties and subspecialties and all age groups and career stages fulfills career and economic goals by working in a short‐term, temporary employment pattern. Locum tenens appeals to physician providers who desire a healthier, more controllable lifestyle.