Naip Tuna

Effect of partial ileal bypass surgery on mortality and morbidity from coronary heart disease in patients with hypercholesterolemia: Report of the program on the surgical control of the hyperlipidemias (posch)

BACKGROUND AND METHODS The Program on the Surgical Control of the Hyperlipidemias (POSCH), a randomized clinical trial, was designed to test whether cholesterol lowering induced by the partial ileal bypass operation would favorably affect overall mortality or mortality due to coronary heart disease. The study population consisted of 838 patients (417 in the control group and 421 in the surgery group), both men (90.7 percent) and women, with an average age of 51 years, who had survived a first myocardial infarction. The mean follow-up period was 9.7 years. RESULTS When compared with the control group at five years, the surgery group had a total plasma cholesterol level 23.3 percent lower (4.71 +/- 0.91 vs. 6.14 +/- 0.89 mmol per liter [mean +/- SD]; P less than 0.0001), a low-density lipoprotein cholesterol level 37.7 percent lower (2.68 +/- 0.78 vs. 4.30 +/- 0.89 mmol per liter; P less than 0.0001), and a high-density lipoprotein cholesterol level 4.3 percent higher (1.08 +/- 0.26 vs. 1.04 +/- 0.25 mmol per liter; P = 0.02). Overall mortality and mortality due to coronary heart disease were reduced, but not significantly so (deaths overall [control vs. surgery], 62 vs. 49, P = 0.164; deaths due to coronary disease, 44 vs. 32, P = 0.113). The overall mortality in the surgery subgroup with an ejection fraction greater than or equal to 50 percent was 36 percent lower (control vs. surgery, 39 vs. 24; P = 0.021). The value for two end points combined--death due to coronary heart disease and confirmed nonfatal myocardial infarction--was 35 percent lower in the surgery group (125 vs. 82 events; P less than 0.001). During follow-up, 137 control-group and 52 surgery-group patients underwent coronary-artery bypass grafting (P less than 0.0001). A comparison of base-line coronary arteriograms with those obtained at 3, 5, 7, and 10 years consistently showed less disease progression in the surgery group (P less than 0.001). The most common side effect of partial ileal bypass was diarrhea; others included occasional kidney stones, gallstones, and intestinal obstruction. CONCLUSIONS Partial ileal bypass produces sustained improvement in the blood lipid patterns of patients who have had a myocardial infarction and reduces their subsequent morbidity due to coronary heart disease. The role of this procedure in the management of hypercholesterolemia remains to be determined. These results provide strong evidence supporting the beneficial effects of lipid modification in the reduction of atherosclerosis progression.

Correlation of electrocardiographic and pathologic findings in healed myocardial infarction

A correlative study in 50 cases of healed myocardial infarction compared the 12 lead electrocardiogram with pathologic observations. The electrocardiogram was interpreted according to established Minnesota codes with some modifications. The following conclusions were reached: (1) The electrocardiogram underestimates the extent of myocardial infarction. (2) When a healed myocardial infarct at a specific location is recognized with electrocardiographic criteria, it is likely that there are unrecognized infarcts involving other areas of the left ventricle. (3) Infarctions involving the lateral and inferobasal areas are frequently unrecognized. (4) The electrocardiogram is more likely to miss myocardial infarcts in patients with multiple, than in those with single, electrocardiographically diagnosed infarcts. (5) Apical myocardial infarction does not appear to have specific electrocardiographic findings, other than those related to general infarct localization by electrocardiogram, particularly in patients with anteroseptal or anterolateral infarction. (6) Abnormal Q waves, generally thought to indicate transmural myocardial infarction, are frequently found in subendocardial infarction. (7) The simplified electrocardiographic classification of myocardial infarct site (anteroseptal, inferior, anterolateral) used in this study is preferable to more detailed classifications previously suggested by others.

Genetic factors in the electrocardiogram and heart rate of twins reared apart and together

Important physiologic mechanisms have been thought not to exhibit large amounts of variability, due in part to the assumption that critical biologic functions will have evolved to an evolutionary optimum. The attainment of this optimum would necessarily eliminate individual differences in these variables. Using a sample of monozygotic and dizygotic twins reared apart since birth or early infancy, 12-lead electrocardiographic recordings and vectorcardiograms were obtained. Values of these variables for monozygotic and dizygotic twins reared together were obtained from other studies. Maximum likelihood tests of genetic and environmental components of variation for PR interval, QRS duration, QT interval and ventricular rate indicated a significant contribution of genetic effects (most heritabilities ranged from 30 to 60%), with a negligible contribution from common familial environmental effects.

Electrocardiographic and vectorcardiographic abnormalities in Fabry's disease.

Fabrys disease has been reported to be associated with ECG abnormalities. Thirty-two patients with this disease followed in the University of Minnesota had ECGs and 15 had VCGs. An abonrmal rhythm was observed in two patients on initial examination and four more developed abnormal rhythm on follow-up examinations. A short PR interval (120 msec. or less) was seen in five patients. Thirteen others had a PR interval that was less than 140 msec. Conduction abnormalities involving the A-V node or His bundle or its branches were present in 22 per cent of the patients, most frequently the intraventricular conduction defects progressing to the right bundle branch block. Atrial or ventricular enlargement was seen in 60 per cent of the patients, left ventricular hypertrophy being the most common. ST-T changes with or without chamber enlargement were seen in 10 patients. One patient had an anterior myocardial infarction pattern on his ECG. Hemizygosity was found to be associated with significantly more abnormalities than heterozygosity. The severity of conduction defects also increased with the duration of the disease process. Vectorcardiography in this study did not provide significant additional information other than that observed on the ECG alone. Since the pathology usually reveals myocardial fibers, conduction system, and blood vessels infiltrated with glycosphingolipid, it is believed that lipid infiltration is responsible for conduction defects, chanber enlargement, and other abnormalities. Although Fabrys disease is rate, it may be amenable to therapy; therefore, recognition of cardiac involvement is important.

Congenital corrected transposition of the great vessels: Correlation of electrocardiograms and vectorcardiograms with associated cardiac malformations and hemodynamic states☆

Abstract An electrocardiographic and vectorcardiographic analysis of 37 cases of corrected transposition revealed that characteristic findings were uniformly present in those cases (group I) in which the cardiac apex was on the expected or correct side in relation to the atrial chambers (on the left in situs solitus; on the right in situs inversus). When dextroversion was present (group II), however, many of these features were absent. The findings typical of the 30 cases in group I were initial QRS vectors directed to the left, anteriorly and superiorly; corresponding electrocardiographic findings of Q waves in the right precordial leads (V 4 R and/or V 1 ) and in lead III with absence of the Q wave in lead V 6 ; and corresponding vectorcardiographic findings of absence of the Q loop (represented by a leftward, straight initial efferent limb of the QRS loop in the horizontal plane). Comparative vectorcardiographic analysis of 25 cases in group I (study group) and 78 control cases without corrected transposition but with comparable associated malformations and hemodynamic states, revealed that the aforementioned characteristic vectrocardiographic findings in the study group were effective in distinguishing between the two groups. Otherwise, the patterns of ventricular hypertrophy in the cases with corrected transposition were, in most cases, similar to those of the control cases. The electrocardiographic and vectorcardiographic findings in the 7 cases with dextroversion (group II) were more variable, depending, in part, on the degree of dextroversion. There were, however, such findings as absence of the normal Q loop in the vectorcardiogram in 4 cases and absence of the Q waves in the left precordial leads in 5 cases, which may represent characteristic features of corrected transposition when dextroversion is present. In the over-all approach to the diagnosis of corrected transposition with or without associated cardiac anomalies, the vectorcardiogram proved to be a valuable adjunct to the electrocardiogram in characterizing the electrical events which produce the unusual electrocardiographic features of this condition.

Coronary arteriographic findings in patients with axis shifts or S-T-segment elevations on exercise-stress testing

Abstract The exercise ECGs and coronary arteriograms of 158 patients were examined to evaluate the relationship of exercise-induced axis shifts and S-T-segment elevations to coronary artery disease. Eighteen of the 158 patients had exercise-induced S-T-segment elevations. Seventeen of these 18 patients had severe obstruction of the major coronary artery most compatible with the zone of ischemic localization. This obstruction was greater than 85 per cent in 16 patients and greater than 50 per cent in a seventeenth patient. The remaining patient had a normal coronary arteriogram and the most minimal exercise-induced S-T-segment elevations. Nine of the 158 patients had exercise-induced right axis shifts. Only 4 of these 9 patients had greater than 50 per cent obstruction of a major coronary artery, as compared to 103 of 154 patients in the total group studied. Also, there was no trend toward predominant involvement of any particular coronary artery in these 4 patients. Hence, it appears that this finding is not predictably associated with severe localized coronary artery disease. Only 4 of the 158 patients had exercise-induced left axis shifts. Three of these four patients had complete obstruction of the left anterior descending artery. But the group size was small, and the fourth patient had a normal coronary arteriogram. Hence, it is only possible to suggest that this finding may be associated with severe disease of the left anterior descending artery. The results of coronary artery surgery are discussed in a patient who had both a left axis shift and precordial S-T-segment elevations on his preoperative exercise ECG.

Cardiac dysrhythmias associated with exercise stress testing

Abstract The exercise electrocardiograms and coronary arteriograms of 119 patients were examined to evaluate the significance of dysrhythmias associated with exercise testing. The overall incidence of dysrhythmias before, during and after exercise was 19 percent. The frequency of dysrhythmias was greater (26 percent) in patients with a positive exercise test than in patients with a negative exercise test (11 percent). The results of the exercise tests were correlated with coronary arteriographic findings to detect false positive and false negative results. There was no significant statistical difference in the frequency of dysrhythmias between patients who responded positively and those who responded negatively to exercise. The timing of the dysrhythmia (before, during or after exercise) was not different in the 2 groups. We conclude that dysrhythmias associated with exercise testing should raise the index of suspicion of underlying coronary artery disease but should not be used as a criterion for a positive test.

Vectorcardiographic Studies in Acquired Valvular Disease with Reference to the Diagnosis of Right Ventricular Hypertrophy

The orthogonal vectorcardiogram described by Schmitt and Simonson has been studied in 37 patients with “pure” mitral stenosis.The diagnosis of right ventricular hypertrophy (RVH) could be established from changes in the magnitude, azimuth, and elevations of the initial, middle, and terminal forces, which could not be detected by the routine 12-lead electrocardiogram. This type of[see figure in the PDF file]recording has proved to be of great value in the diagnosis of right ventricular hypertrophy, particularly when the hypertrophy is of mild or moderate degree. Analysis of the instantaneous vectors has proved to be the single most important criterion in the electrocardiographic diagnosis of right ventricular hypertrophy.

Comparison of exercise-positive with recovery-positive treadmill graded exercise tests☆

A treadmill exercise test response may become positive because a diagnostic electrocardiographic ST-segment shift occurred during exercise, or, less often, because it occurred only during the recovery period after exercise had been completed. Factors that may be related to these 2 different responses in subjects enrolled in the Program of Surgical Control of Hyperlipidemia were investigated. No differences were found with regard to age, sex, level or location of Minnesota electrocardiographic Q-QS codes, number of narrowed coronary arteries, presence of collateral coronary artery circulation, ejection fraction, number of abnormally moving left ventricular wall segments, heart rate, systolic and diastolic blood pressure, double product, total exercise time, exercise-induced angina, or maximally achieved exercise heart rate or double product. Thus, the same significance should be attributed to a recovery-positive as to an exercise-positive treadmill test, and electrocardiographic, hemodynamic and angiocardiographic variables do not distinguish between subjects who exhibit these 2 different responses.

Development and evolution of electrocardiographic Minnesota Q-QS codes in patients with acute myocardial infarction

The development of ECG Minnesota Q-QS codes and their subsequent evolution were studied in the first 692 subjects to enter the POSCH program who had had one MI. The mean interval from MI to entry into the study was 2.2 years. Sixty-three percent of the subjects developed the most significant code with the infarction. By the time the subjects entered the study, the codes had commonly regressed to a lower level, disappearing altogether in 34%. The likelihood of complete regression varied inversely with the significance of the code. There was no significant difference between the groups with disappearance and with retention of a Q-QS code as to time since MI, the extent of coronary arterial disease, or the age or sex of the subject. In about half of the subjects the original code did not change with time and in 21% to 44% the code increased to one of a higher level of significance.