Irving M. Liebow

Arteriosclerotic heart disease in diabetes mellitus; a clinical study of 383 patients.

Abstract 1.1. A cardiac survey was made of 383 living, outpatient diabetics. The findings in regard to clinically diagnosed arteriosclerotic heart disease in these patients are reported. 2.2. Forty-two per cent had arteriosclerotic heart disease. An additional 16.2 per cent had arteriosclerosis of the aorta. 3.3. Angina pectoris was found in 10.2 per cent; 6.8 per cent had myocardial infarction. 4.4. The prevalence of arteriosclerotic heart disease was related in positive manner to sex, age and the presence of hypertension. 5.5. The prevalence of arteriosclerotic heart disease was not related to the total serum cholesterol level, the degree of control of the diabetes, the patients weight, the daily insulin dose or the duration of the diabetes.

Coronary Heart Disease in the Pima Indians: Electrocardiographic Findings and Postmortem Evidence of Myocardial Infarction in a Population with a High Prevalence of Diabetes Mellitus

The frequency of electrocardiographic evidence of coronary heart disease (CHD) and the rate of autopsy-proved myocardial infarction were determined in the Pima, a tribe of American Indians with a high prevalence of diabetes mellitus. The electrocardiograms of 701 Pimas, aged 40 years and over (85 per cent of the adult reservation population, 45 per cent of whom had diabetes) were read according to the Minnesota Code, and 120 postmortem examinations were reviewed for evidence of myocardial infarction. The frequency of CHD as evidenced by major Q-wave changes in the Pima (1.6/100) was about one-half that found in Tecumseh, Michigan (p<0.10). The relatively low rate of myocardial infarction at autopsy (15 per cent of males and 8 per cent of females aged 40 years and over) was consistent with the low prevalence of Q-wave changes. The subjects with diabetes had a higher rate of CHD than nondiabetics, both electrocardiographically and at postmortem examination, although the differences were not statistically significant. The low prevalence of CHD in the living Pima and the low rate of infarction at autopsy indicate that this tribe has a low frequency of CHD despite the extraordinarily high prevalence of diabetes mellitus.

Insulin Treatment, Endogenous Insulin Concentration, and ECG Abnormalities in Diabetic Pima Indians: Cross-Sectional and Prospective Analyses

The prevalence and incidence of CHD, defined by ECG abnormalities according to the Tecumseh criteria for Minnesota Codes, were determined in Pima Indians >25 yr of age. In a cross-sectional analysis, the age-sex-adjusted prevalence (± SE) of ECG abnormalities was higher in 1454 NIDDM patients (6.86 ± 0.65%) than in 1696 nondiabetic subjects (3.23 ± 0.63%; prevalence rate ratio = 2.12; 95% Cl 1.39–3.25). In a prospective analysis, the age-sex-adjusted incidence (± SE) of ECG abnormalities was higher in 824 NIDDM patients (12.77 ±1.67) than in 935 nondiabetic subjects (5.93 ± 1.43 cases/1000 person-yr; incidence rate ratio = 2.15; 95% Cl 1.26–3.69). The prevalence of ECG abnormalities in insulin-treated NIDDM patients was significantly higher than in NIDDM patients not treated with insulin (age-sex-adjusted OR = 2.83; 95% Cl 1.84–4.33); and this association persisted when adjusted for other factors such as sBP, BMI, duration of diabetes, serum cholesterol concentration, and oral hypoglycemic agents (OR = 2.12; 95% Cl 1.34–3.37). In the prospective analysis, the incidence of ECG abnormalities in NIDDM patients treated with insulin was higher than in those NIDDM patients not treated with insulin, but, when controlled for age, sex, duration of diabetes, and oral hypoglycemic agents in a proportional-hazards model, the relationship with insulin treatment was not statistically significant (incidence rate ratio = 1.36; 95% Cl 0.80–2.31). This suggests that insulin treatment may be a marker of more severe diabetes, and that factors associated with clinical indications for insulin treatment, rather than insulin treatment per se, are related causally to CHD. On the other hand, endogenous fasting and 2-h postload serum insulin concentrations were not associated with ECG abnormalities among 761 NIDDM patients not treated with insulin nor among 1226 nondiabetic subjects. Furthermore, in the prospective study, neither endogenous fasting nor 2-h postload serum insulin was associated with the subsequent development of ECG abnormalities in NIDDM patients or nondiabetic subjects.

Cardiac complications of diabetes mellitus

Abstract 1.1. The cardiac complications of diabetes mellitus are discussed under the following headings: (1) coronary arteriosclerosis, (2) diabetic acidosis and (3) hypoglycemia. 2.2. There is a higher incidence of coronary arteriosclerosis and its clinical manifestations among diabetics than among non-diabetics. This higher incidence is more marked in women. The duration of the diabetes is probably the greatest single factor in the occurrence of coronary arteriosclerosis. 3.3. Cardiovascular collapse occurs frequently in diabetic acidosis. Prevention and treatment of such shock consists of the administration of adequate amounts of water, sodium chloride, protein and potassium. 4.4. Insulin reactions are associated with cardiac complications particularly in the older age groups. Completely aglycosuric control of elderly diabetics by the use of insulin is not desirable.

Digitalis and the normal work electrocardiogram

Abstract 1. 1. Exercise electrocardiograms were made of fourteen normal persons before and after digitalization. 2. 2. When the subjects were digitalized, exercise caused a general depression of the S-T junction which in four instances was distinctly abnormal. Changes in T waves and rhythm also occurred. 3. 3. It is therefore imperative that the digitalis effect on work electrocardiograms be not confused with work electrocardiograms which show the result of myocardial ischemia due to coronary artery disease.

Factors influencing the T wave of the electrocardiogram. An experimental study employing intracavitary and extraventricular (epicardial) leads

Abstract The effects of cooling and heating the endocardium and epicardium have been studied by the use of intra- and extraventricular exploring unipolar leads. Direct evidence has been obtained that changes in the electrical state of the endocardial muscular lamina modify the form of the electrocardiogram. Changes in the T wave can be produced by changing the rate and order of endocardialepicardial laminar repolarization. Negative T waves occurred where the exploring electrode subtended areas which had relatively or absolutely retarded repolarization; positive T waves occurred where the exploring electrode subtended areas which had relatively or absolutely accelerated repolarization. It was found that negative T waves occurred: 1. A. In the cavity (1) when the endocardium was cooled; (2) when the endocardium was not altered, but the epicardium was heated. 2. B. On the epicardium or precordium (1) when the epicardium immediately under the electrode was cooled; (2) when the endocardium subjacent to the epicardial exploring electrode was heated; (3) when the endocardium of the opposite wall was cooled. It was found that positive T waves occurred: 1. A. In the cavity (1) when the endocardium was heated; (2) when the epicardium was cooled. 2. B. On the epicardium or precordium (1) when the subjacent epicardium was heated; (2) when the subjacent endocardium was cooled. The relation of these results to the modern concept of altered repolarization in an extensive conducting medium are discussed. The spatial relation of the exploring electrode to a theoretical surface at the junction of the normal and altered areas is used to account adequately for the findings. The practical value of these observations is discussed. The present results confirm and extend previous observations on the contribution of the subendocardial myocardium to the electrocardiogram.

Isolated bilateral simultaneous dissection of the renal arteries

Abstract 1. 1. A case of intramural renal artery dissection is reported. The lesion was simultaneously bilateral, was not preceded by trauma and was not associated with intramural dissection of the aorta. It is believed to be the first case of isolated, non-traumatic intramural dissection of the renal artery to be reported. 2. 2. The nature of the arterial disease, the blood pressure changes and the marked elevation of blood nitrogen are discussed.

Factors influencing the T wave of the electrocardiogram

Abstract 1.1. The effects of intra-arterial, intravenous, and intracardiac injection of acetylcholine upon the blood pressure and upon intracavitary and extracavitary leads of the electrocardiogram of the intact anesthetized dog were studied. 2.2. The intra-arterial route never resulted in early change in the electrocardiogram. 3.3. Minute doses were found to be effective: 0.01 μg caused fall in blood pressure; 0.1 μg caused T a change; 5 μg resulted in change of T. 4.4. Acetylcholine caused very early T a depression and increase in amplitude of the T wave in extracavitary leads. The expected reciprocal changes were seen in intracavitary leads. These changes were independent of any change in blood pressure and occurred in the absence of chronotropic effect of acetylcholine. 5.5. The possible mechanisms of these actions of acetylcholine are discussed.

The electrocardiogram in lupus erythematosus disseminatus

Abstract Abnormalities of the electrocardiogram in patients with lupus erythematosus disseminatus have been noted by several authors in case reports. These abnormalities have consisted of low voltage, increased P-R interval, increase in left axis deviation, low or inverted T waves and premature beats. This report presents the electrocardiographic findings in eight autopsied cases of lupus erythematosus disseminatus. All abnormalities noted above were found in this group with the exception of premature beats. In addition, change of axis from normal to right axis deviation occurred. There was also a general tendency toward prolongation of the Q-T interval; in two patients Q-T was abnormally prolonged. Low voltage was not as common as reported in other series. Electrocardiographic changes were seen as long as ten months before death. In those patients in whom a series of records was obtained the electrocardiograms became progressively and increasingly abnormal. In three of eight patients in whom there was anatomic abnormality of the heart there was no change in the electrocardiogram. In all of these, however, there was no series of records; only a single electrocardiogram was available for study.

Myocardial infarction in the practices of a group of private physicians-IV: Factors related to the longevity of patients with myocardial infarction during the first five years

Abstract The mortality which occurred during the first five years following 156 first myocardial infarctions and 62 later than first infarctions has been described. Using relative survival rates it has been shown that: 1. 1. The excess mortality was very great during the first few weeks after the infarction, and continued as an excess but at a lower level throughout the five years. 2. 2. Survivorship following later than first infarctions was less favorable than following first infarctions during the first six months, but after that no statistically significant difference was found. 3. 3. Men and women had about the same prognosis for the five year period. 4. 4. Congestive heart failure in combination with a new arrhythmia was especially serious. In each period of time after the infarction, the survivors starting the period had a high mortality during the period. 5. 5. This was also true of congestive failure in the absence of arrhythmia, but to a reduced degree. Congestive failure contributed to a continuing poor prognosis whether it existed prior to the onset of the infarction or developed as an early complication of it. 6. 6. The number of patients with diabetes was small, and subdivision into smaller groups was not feasible. However, even those diabetics who had no complications during the first month had a relatively poor five year prognosis.