Clinically unrecognized ventricular dysfunction in young diabetic patients.

Left ventricular function at rest and during supine bicycle exercise was assessed by gated radionuclide angiography in 20 diabetic patients and 18 normal control subjects without clinical evidence of heart disease. The diabetic patients were aged 21 to 44 years and all except one used insulin. No subject developed chest pain or electrocardiographic changes during exercise. Both groups had a similar rest and exercise heart rate and blood pressure, and both achieved similar work loads. The control group had an ejection fraction at rest of 65.4 +/- 6.2% (mean +/- SD) and only 1 of 18 showed a decrease with exercise; peak exercise ejection fraction averaged 77.1 +/- 7.8%. The diabetic group had a mean ejection fraction at rest of 63.7 +/- 6.5%, similar to that of the control group, but 7 of 20 showed a decrease during exercise; the exercise ejection fraction averaged 67.7 +/- 9.7%, significantly lower than that of the control group (p less than 0.01). The diabetic patients varied widely in ejection fraction response to exercise, ranging from an increase of 25% to a decrease of 21%. This response did not correlate with age, sex, duration of diabetes, smoking, retinopathy, exercise heart rate, blood pressure or rate-pressure product, work load attained or ejection fraction at rest. These data suggest that approximately one-third of patients with diabetes have subclinical left ventricular dysfunction without correlation to risk factors for atherosclerosis or other diabetic complications. Whether this is due to unrecognized coronary artery disease or primary myocardial disease remains unknown.

Prinzmetal's angina with coronary artery spasm. Angiographic, pharmacologic, metabolic and radionuclide perfusion studies.

We studied the effects of coronary artery spasm on perfusion of the microvasculature in a patient with Prinzmetal's angina. Intracoronary injections of 99mTc and 131I-labelled macroaggregated human serum albumin were performed (1) at rest, (2) during spontaneous angina, (3) after the administration of nitroglycerin and (4) during pacing-induced spasm and the resultant scans compared. The resting scan was normal. Pain and spasm were associated with a perfusion defect that was localized to the anterior and inferior walls of the left ventricle. The localization of the perfusion defect corresponded with angiographically demonstrated spasm involving left anterior descending and distal circumflex coronary arteries. A subsequent myocardial infarction was localized by 43K scanning to the same perfusion area. Metabolic and parasympathetic stimulation studies were performed but were inconclusive. The patient's recurrent pains were ultimately controlled with large oral doses of isosorbide dinitrate.

Rest and exercise ventricular function in adults with congenital ventricular septal defects.

Rest and exercise right and left ventricular function were compared using equilibrium gated radionuclide angiography in 19 normal sedentary control subjects (mean age 28 years, range 22 to 34) and 34 patients with hemodynamically documented congenital ventricular septal defect (VSD) (mean age 27 years, range 20 to 40). The 34 patients with VSD were divided into 3 groups: those in Group 1 (17 patients) had pulmonary to systemic blood flow ratios of less than 2 to 1; those in Group 2 (12 patients) had prior surgical closure of VSD (mean interval from surgery 17 years, range 9 to 22), and those in Group 3 (5 patients) had Eisenmenger's complex. Gated radionuclide angiography was performed at rest and during each level of graded supine bicycle exercise to fatigue. Heart rate, blood pressure, maximal work load achieved, and right and left ventricular ejection fractions were assessed. The control subjects demonstrated an increase in both the left and right ventricular ejection fractions with exercise (0.70 +/- 0.07 to 0.79 +/- 0.05 and 0.46 +/- 0.06 to 0.57 +/- 0.04; p less than 0.001 for left and right ventricles, respectively). All study groups failed to demonstrate an increase in ejection fraction in either ventricle with exercise. Furthermore, resting left ventricular ejection fraction in Groups 2 and 3 was lower than that in the control subjects (0.59 +/- 0.09 and 0.54 +/- 0.06 versus 0.70 +/- 0.07; p less than 0.001) and resting right ventricular ejection fraction was lower in Group 3 versus control subjects (0.30 +/- 0.07 versus 0.46 +/- 0.06; p less than 0.001). Thus (1) left and right ventricular function on exercise were abnormal in patients with residual VSD as compared with control subjects; (2) rest and exercise left ventricular ejection fractions remained abnormal despite surgical closure of VSD in the remote past; (3) resting left and right ventricular function was abnormal in patients with Eisenmenger's complex; (4) lifelong volume overload may be detrimental to myocardial function.

Malignant hyperthermia susceptibility. A light and electron microscopic study of endomyocardial biopsy specimens from nine patients.

Cardiomyopathy develops in some individuals who have a susceptibility to malignant hyperthermia. We studied right ventricular endomyocardial biopsy specimens from nine patients defined as having this disorder because of positive caffeine contracture tests on skeletal muscle biopsy specimens. Three patients had clinical evidence of cardiomyopathy and six did not. Light microscopy showed cytoplasmic contraction bands, perinuclear clearing, and a mild to moderate variation in myocyte and nuclear size. Ultrastructurally cytoplasmic contraction bands were associated with cardiac villi, myofiberlysis, and myofibrillolysis. These changes and occasional breaks in the sarcolemma were regarded as artefacts of the biopsy procedure. Megamitochondriosis with accompanying degenerative changes in the mitochondria were also seen and probably indicate increased cell metabolism; vacuolation of the cytoplasm was regarded as an "aging" phenomenon. Thus, the biopsy specimens were abnormal, but the changes were artefactual or nonspecific and were not unique to this group of patients. Biopsy did not provide a morphological explanation for abnormal cardiac function.

Repair of major intracardiac anomalies associated with atrioventricular discordance.

Thirty-five patients with atrioventricular (AV) discordance underwent repair of major intracardiac defects. Ventricular septal defect (VSD) was the most frequently encountered lesion, present alone or in combination with other lesions in 86% of these patients. Pulmonary stenosis (51%) and tricuspid insufficiency (37%) were the other lesions encountered. The initial operative mortality of 8.6% is approaching that for these same defects when repaired in the patient with normal atrioventricular connections. However, the late mortality of 19% with an average follow-up of 4.4 years is higher than expected in the absence of AV discordance. Reoperation for residual or recurrent defects was required in 9 of the 32 survivors and was associated with a mortality of 33%. Seven of the 9 reoperations were required for tricuspid valve dysfunction. Elective repair of major anomalies in association with AV discordance can be accomplished safely, but these patients require careful long-term follow-up in anticipation of late problems.

Management of transposition after the baffes procedure: a case report and review of our experience.

A case report details the operative technique used in the repair of complete transposition of the great arteries (TGA), ventricular septal defect (VSD), and pulmonary stenosis in a patient who had had Baffes procedure previously. Experience in managing 10 patients with complete TGA who had undergone a Baffes procedure is discussed. Four patients with a large VSD had pulmonary vascular disease. The condition of 1 of them was improved by a palliative Mustard operation. Four children with isolated TGA underwent a successful modified Mustard repair. The 2 remaining patients had a VSD and pulmonary stenosis; in 1 the condition was palliated by a Glenn shunt. The other is the subject of the case report. The mean interval between the Baffes procedure and the second operation was 11 years. There was 1 late death after secondary repair. Follow-up in the remaining 6 patients at a mean of 10.6 years indicates a favorable outcome.

Primary repair of Fallot's tetralogy in an older adult: a 20-year follow-up.

A patient with tetralogy of Fallot who presented at 58 years of age is described. Following surgical intracardiac repair he had 20 years of improved functional capacity. Though such surgery is now usually performed in infancy, the literature indicates that surgical correction of tetralogy of Fallot in appropriate adults is associated with low mortality and good long-term results.

PTCA in elderly patients: hospital events.

BACKGROUND: Medical treatment of the elderly is changing to include the aggressive management of coronary artery disease with percutaneous transluminal coronary angioplasty. OBJECTIVE: The purpose of this study was to review major hospital events of patients aged 70 years or more, who underwent a first percutaneous transluminal coronary angioplasty. METHODS: A retrospective medical record review was done of 246 consecutive patients of 70 years or more, from January 1985 to December 1988, at a tertiary care community hospital. Adverse events and the factors that influenced outcome were identified. RESULTS: Of 246 patients (age range, 70-85 years, mean = 73.6), 19 died, 4 had a cerebral vascular accident, 11 had a transfusion and 11 underwent coronary artery bypass grafting. Sixteen patients had acute vessel closure and 8 died. Twenty-five patients had one event and 21 patients had more than one. DISCUSSION: The event rate after percutaneous transluminal coronary angioplasty in the elderly is high. CONCLUSIONS: Knowledge of the factors that influence adverse events (diagnostic category, success of procedure, degree of coronary artery disease and age) will assist the critical care team to plan and implement appropriate care.

Electrocardiographic abnormalities associated with malignant hyperthermia susceptibility.

Serial ECG's were reviewed in 93 consecutive patients who were proven to be susceptible to malignant hyperthermia by caffeine contracture and ATP depletion tests on skeletal muscle biopsies, but who were without a history of pyrexic crises. There were 46 males and 47 females with a mean age of 33 years. Abnormal ECG's were found in 26 of the patients, with conduction defects in 14, repolarization abnormalities (non-specific ST-T changes) or "Q" waves in nine and increased voltages suggesting left ventricular hypertrophy in three (in the absence of hypertension). An abnormal ECG in a young patient may reflect malignant hyperthermia susceptibility.

Effect of intracoronary glyceryl trinitrate on perfusion distribution in the collateralised human myocardium.

The effect on myocardial perfusion distribution of intracoronary glyceryl trinitrate in a dose (60 micrograms) insufficient to cause alterations in systemic blood pressure or heart rate was studied in eight patients with angiographically demonstrated collaterals from the left coronary system to the distal right coronary artery. Double isotope imaging using technetium-99m and iodine-131 labelled albumin macroaggregates allowed each patient to serve as his own control. The reproducibility of the imaging and data handling techniques was shown in 12 control patients. Glyceryl trinitrate caused a significant diminution in the collateral-mediated fractional perfusion while increasing that of the native coronary bed.

Angiographic demonstration of blood supply of right atrial myxoma.

A 53-year-old woman underwent cardiac catheterization for assessment of coronary arterial disease. An unexpected finding of a gradient between right atrium and right ventricle led to the discovery of an unsuspected right atrial myxoma. The diagnosis was established by the presence of a filling defect in the right atrial angiocardiogram and by the demonstration of "tumour vessels" by selective right coronary angiography. Selective coronary angiography can visualize the blood supply to an intracardiac tumour and thus confirm the diagnosis preoperatively.

Myocardial infarction in coronary artery surgery.

Myocardial infarction has been noted as a frequent complication of coronary artery surgery in many review series, although its causes are uncertain. Follow-up of 100 patients at 19.7 months (mean) after coronary bypass surgery identified 15 patients with perioperative myocardial infarction as judged by new, significant Q waves after surgery. There were no significnat differences in age, preoperative anginal class, previous infarction, presence of hypertension, hyperlipidemia, or frank glucose intolerance compared with the 85 patients without infarction. Nor was there a significnat difference in coronary artery score, left ventricular end-diastolic pressure, cardiac index, or presence of collaterals. Cardiopulmonary bypass time, duration of anoxic arrest, and number of vessels grafted did not differ. Perioperative infarction always occurred in the territory of a grafted vessel and not in comparably compromised, nongrafted areas. In 13 cases new Q waves appeared in the first 24 hours, and myocardial infarction was not clinically suspected. Eight of the 15 grafts at risk were patent at late follow-up. Mean ejection fraction was not significantly changed postoperatively, but affected segmental wall motion declined in most cases. Five patients with perioperative infarction but no patent grafts improved by only 1 NYHA class (mean), but ten patients with infarction and one or more grafts patent improved by 2.9 NYHA classes (mean). Perioperative infarction could not be correlated with currently recognized patient and operative risk factors. The consistent anatomical relationship suggested that the grafting procedure itself was critical to the occurrence of distal segmental infarction.