Anterior conduction delay: a possible cause for prominent anterior QRS forces.

Prominently anterior QRS forces often present a diagnostic dilemma. Frequently, right ventricular forces may be eliminated on clinical grounds and dorsal infarction is therefore suspected, especially in a clinical setting of coronary artery disease. In five such patients studied angiographically, the coronary disease was concentrated in the left anterior descending artery and the ventricular dysfunction confined to the anterior wall of the left ventricle. In a sixth case, the prominent anterior forces were observed intermittently together with left anterior hemiblock. These observations, in addition to serial studies following surgery, strongly suggest that the mechanism for prominent anterior QRS forces in these cases is conduction delay in an anterior division of the left bundle branch system.     

Correlation of heart size with clinical and hemodynamic findings in patients with coronary artery disease.

The clinical, hemodynamic, and angiographic findings were correlated with the heart size in 207 patients with proved coronary artery disease. Cardiomegaly was noted in 34 patients and normal heart size in 173. In these two groups, the patients' age range, duration of disease, and history of myocardial infarction were similar. There was no statistical difference in incidence of shortness of breath, hypertension, left ventricular hypertrophy, or abnormal glucose tolerance. Patients with cardiomegaly had a significantly higher incidence of congestive heart failure (26 per cent) as compared to patients with normal heart size (2.9 per cent) (P less than 0.001). Patients with enlarged heart presented a high incidence of anterior wall or multiple myocardial infarction (73 per cent) (P less than 0.001). The cardiomegaly group had a high incidence of elevated end-diastolic volumes, elevated end-diastolic pressures, and diminished ejection fractions when compared to patients with normal heart size (P less than 0.01). Double and triple coronary artery disease was more frequent in patients with cardiomegaly and total coronary score was also higher in this group (P less than 0.005). Asynergy was present in 55 per cent of patients with normal heart size but in 82 per cent of those with enlarged hearts (P less than 0.01). The group of patients with cardiomegaly and documented congestive heart failure had ejection fractions less than 0.30. Cardiac catheterization is probably not advisable in these patients in the absence of associated significant mitral regurgitation, ventricular septal defect, or ventricular aneurysm.     

Postextrasystolic aortic pressure pulse response in coronary artery disease.

The response of the aortic systolic pressure after an extrasystole was evaluated in 100 consecutive patients with coronary artery disease. The patients were divided into four groups depending on the response of the first postextrasystolic beat. Group IA (45 patients), had lower systolic pressure, whereas group IB (40 patients), had a similar systolic pressure in the postextrasystolic beat, as compared to beats preceding the extrasystole. Group IIA (12 patients) and group IIB (3 patients), demonstrated an increased systolic pressure in the first postextrasystolic beat with subsequent beats in group IIB, also demonstrating pulsus alternans. Congestive heart failure and cardiomegaly were significantly more frequent in group II, as compared to group I patients. In group IIA and IIB, triple vessel disease was present in 83 and 100 per cent, respectively, as compared to 44 per cent in group I patients. Left ventricular end-diastolic pressure (mm. Hg) was 14 ± 6 and 12 ± 7 in group IA and IB respectively, as compared to 19 ± 9 (p < 0.025) in group IIA and 31 in group IIB. Comparing groups IA and IB with each other for cardiac output, stroke volume, end-diastolic volume and ejection fraction, revealed no significant difference. The cardiac output (L./min./M.²) was 2.2 ± 0.6 for group IIA, as compared (p < 0.01) to 2.8 ± 0.5 and 2.9 ± 0.5 in groups IA and IB. Stroke volume (ml./M.²) and ejection fraction were 30 ± 10 and 0.30 ± 0.08, respectively, for group IIA, which is signficantly less, as compared to group I patients. The end-diastolic volume (ml./M.²) in group IIA was 102 ± 28, which is significantly (p < 0.001) higher, as compared to group IA and IB. All patients in group IIB had an abnormal cardiac output, end-diastolic volume and ejection fraction. Thus, the differences in response between group I and group II patients to an extrasystole clearly define two distinct hemodynamic groups. The responses observed to an extrasystole are best explained by variable response of each group to postextrasystolic potentiation and aortic impedance.     

Relation of left ventricular contractile patterns in coronary artery disease to the electrocardiogram and vectorcardiogram

Two hundred thirty patients with coronary artery disease (CAD) were studied with left ventriculography, coronary arteriography, electrocardiography (ECG) and vectorcardiography (VCG) to determine how well left ventricular (LV) contractile defects could be predicted from the ECG-VCG patterns and how this was related to the coronary disease location and severity. Of 124 patients with infarction patterns on ECG-VCG about 50% had LV contractile defects localized to the corresponding ECG-VCG abnormalities, i.e., antero-apical asynergy with anterior infarction patterns, inferior asynergy with inferior infarction patterns, or antero-apical plus inferior asynergy with anterior plus inferior patterns. About 20% in each infarction group had unexpected synergy on ventriculography except for patients with dorsal infarction patterns (synergy in 68%) who are discussed as a special problem. Another 25-30% of patients had more extensive contractile abnormality than indicated by the ECG-VCG patterns. In 106 patients with left ventricular hypertrophy, normal QRS-abnormal T and normal QRS-T on ECG-VCG, 65-70% had synergy. However, 30-35% had asynergy in various combinations not suspected from the ECG or VCG. Coronary artery disease severity was less pronounced in patients with synergy than with asynergy and single vessel disease was more common in the former, 47% versus 18-30% in the latter. However, coronary artery disease severity was the same for all ECG-VCG groups except for anterior plus inferior infarction patterns where it was most severe.     

Clinical and hemodynamic aspects of single vessel coronary artery disease

Two-hundred consecutive patients with arteriosclerotic heart disease underwent complete clinical and hemodynamic evaluation. Fifty-two patients (26 per cent) had significant single vessel coronary artery disease and were compared to 148 patients with more extensive coronary artery disease and to a group of 14 normal patients. The single vessel disease group, when compared to the diffuse disease group, was characterized by a shorter duration of angina pectoris, lower frequency of a history of congestive heart failure or cardiomegaly, and a lower frequency of electrocardiographic (ECG) evidence of a transmural myocardial infarction. The combination of angina pectoris for three or more years with cardiomegaly was the only factor which completely separated the two coronary disease groups. Cardiomegaly, when present in single vessel involvement, was always due to left anterior descending (LAD) disease, together with an anterior infarction on ECG and left ventricular asynergy. The single vessel disease group included 32 patients with LAD disease, 17 with RCA, and 3 with circumflex artery involvement. Resting hemodynamics in these 52 patients (other than a higher left ventricular end-diastolic pressure and wall stress) were not significantly different from hemodynamics in a normal group. Patients with diffuse disease were characterized by many hemodynamic alterations and by left ventricular (LV) asynergy, when compared to the single vessel disease or normal groups. The diffuse disease group had a lower ejection fraction (EF) and an increased frequency of LV asynergy and coronary collateral circulation than did the LAD group. In the single vessel disease group LV asynergy did not correlate with the ECG. LV synergy, however, was not found in any patient in the LAD group with abnormal Q waves on ECG. The single vessel disease group included only five patients with increased end-diastolic volume (EDV) and all had LAD involvement, increased LV end-diastolic pressure, and decreased EF. The remaining 47 patients with normal LV-EDV revealed that the LAD group had abnormal pressure-volume relationships, indicating a decreased compliance of the left ventricle.     

Percutaneous transluminal coronary angioplasty: Its potential impact on surgery for coronary artery disease

The potential impact of percutaneous transluminal coronary angioplasty on surgery for angina pectoris was evaluated in 500 consecutive patients referred because of intractable symptoms. A positive lesion, that is, one appropriate for percutaneous transluminal coronary angioplasty, was defined as proximal, discrete, segmental, subtotal, noncalcific and stenotic. Significant disease was observed in 1,079 major coronary arteries, of which 9.4 percent were not appropriate for bypass surgery. Positive lesions were observed in 115 arteries (10.7 percent); these were in the left anterior descending artery in 60; in the right coronary artery in 37 and in the left circumflex artery in 18 cases. Main left coronary artery disease was present in 31 patients with six lesions appropriate for coronary angioplasty. Of these six patients none had isolated left main coronary artery disease. Operable coronary lesions were noted in 474 patients of whom 105 (22 percent) had positive lesions appropriate for angioplasty. The age of patients with such lesions was not significantly different from that of the remaining patients. However, the duration of clinical heart disease was significantly (p <0.01) shorter in those with positive lesions, with the frequency of such lesions inversely related to duration of disease, and myocardial infarction was less frequent in those with angioplastic lesions (28.6 versus 43.5 percent, p <0.01). An ideal patient for percutaneous transluminal coronary angioplasty was defined as one with a positive lesion in all operable coronary arteries. Thus, 40 patients were considered ideal for this procedure and represented 8.4 percent of operable candidates. Thirty patients had single vessel disease (of the left anterior descending artery in 19, the right coronary artery in 8 and the circumflex artery in 3) and 10 had disease of two vessels. No patient with triple or left main coronary artery disease was ideally suited for percutaneous transluminal coronary angioplasty. The only factor that distinguished the patient ideally suited for angioplasty from the remaining patients was a shorter duration (2.0 versus 4.1 years) of clinical disease (p <0.01) and a lesser frequency (15 versus 43 percent) of myocardial infarction (p <0.01). Seven additional patients were noted as being less ideal for coronary angioplasty, but still potential candidates. It is concluded that percutaneous transluminal coronary angioplasty may play a role in only 8 to 10 percent of patients with angina pectoris.     

Results of aortocoronary bypass grafting in patients with subendocardial infarction: late follow-up.

Twenty-eight patients with subendocardial infarction (Group A) were compared with 28 patients with unstable angina (Group B) and 28 with stable angina (Group C) matched for age and sex. The three groups did not differ in prevalence of diabetes, hypertension, old infarction or duration of disease. There were no significant differences in number of diseased vessels, coronary score, abnormal left ventricular wall motion or left ventricular end-diastolic pressure. Angiograms performed 2 weeks postoperatively revealed closure of 3 of 31 grafts (16 patients) in Group A, closure of 3 of 34 grafts (17 patients) in Group B and closure of 6 of 50 grafts (22 patients) in Group C (differences not significant). Postoperative angiograms showed improved wall motion in 37 percent of Group A, 53 percent of Group B and 36 percent of Group C (differences not significant). Postoperative new Q waves appeared in one hospital in Group A and in two patients in Groups B and C. There were no hospital or late deaths. In a mean follow-up period of 29 months, 68 percent of patients in Group A, 61 percent in Group B and 54 percent in Group C were asymptomatic. Thus, bypass grafting was performed with similarly low mortality and morbidity in patients with subendocardial infarction and in those with angina; more than one third of postoperative angiograms in the three groups showed improved wall motion; and late follow-up studies demonstrated functional improvement in the majority of patients in all three groups.     

Quantitative thallium-201 imaging: Limitations in detecting pathophysiologically significant obstructive coronary artery disease

Washout of thallium-201 after stress testing has been proposed as a method of detecting abnormal zonal myocardial perfusion without relating it to a reference “normal” area. Therefore, 18 patients with single-vessel coronary artery disease, undergoing percutaneous transluminal coronary angioplasty, underwent maximum stress testing and thallium imaging. A myocardial perfusion defect was seen in the immediate postexercise images in all 19 zones (one patient studied twice) supplied by the vessel with the obstructive lesion. Delayed images showed improvement in 15 of the 19 segments. Of the four zones which did not improve, three had evidence of a prior nontransmural myocardial infarction. Quantitative analysis of washout curves showed that counts decreased in 17 of 19 zones after background subtraction and in all 19 zones if background was not subtracted. In the corresponding normal zones directionally similar decreases in counts were seen. Thus washout characteristics were similar for both diseased and normal zones. These data indicate that washout curves are limited in their ability to detect the presence of a physiologically significant lesion.     

Unusual complications of coronary bypass surgery.

Five patients after coronary bypass surgery developed unusual complications. Three developed new apical thrombi which are thought to be due to the trauma of the left ventricular vent or deterioration of the left ventricular contraction. Significant new mitral regurgitation in one patient probably is secondary to papillary muscle dysfunction as the result of stenosis distal to anastomoses. The leakage of angoigraphic material around distal anastomatic site is due to technical error. Although these unusual complications are very rare, however, they should be considered as potential source of morbidity in asymptomatic patients who leave the hospital after bypass surgery.     

Comparative study of the postoperative flow in the saphenous vein and internal mammary artery bypass grafts.

Postoperative coronary bypass flow was evaluated in two groups of randomly selected patients with grafts to the left anterior descending artery (LAD). Saphenous vein bypass grafts were placed in 27 patients and internal mammary artery grafts in 25 patients. Postoperative flow studies were performed in both groups with roentgendensitometric methods based on the transit time of radiopaque media along the graft plus the mean graft diameter. There was no significant difference between the two groups of patients for age, duration of symptoms, or the frequency of hypertension, diabetes mellitus, prior myocardial infarction, or cardiomegaly. Intraoperative bypass flows were 75+/-27 and 77+/-24 ml. per minute for the saphenous vein group (SVG) and internal mammary artery group (IMAG), respectively. There was no significant difference in the heart rate or mean aortic pressure at the time of the roentgendensitometric flow study. The mean graft diameters were 3.0+/-0.5 and 1.9+/-0.3 mm. for the SVG and IMAG, respectively (p less than 0.001). The ratios of graft diameter to LAD diameter were 1.9+/-0.3 and 1.2+/-0.2 for the SVG and IMAG, respectively (p less than 0.001). The roentgendensitometric postoperative flows were 68+/-27 ml. per minute in the SVG and 46+/-16 ml. per minute in the IMAG (p less than 0.01). The present study indicates that flow in significantly higher in saphenous vein than in internal mammary artery bypasses and that the difference in flow may in part be explained on the basis of the graft diameter.     

Coronary ectasia: incidence and results of coronary bypass surgery.

Coronary angiograms were performed in 1,660 patients between the ages of 27 and 84 years. Coronary ectasia was noted in 42 (2.5 per cent) patients. These 42 patients were compared with an equal number of patients with coronary artery disease, matched for age and sex. There were no significant differences in numbers of vessels involved with significant disease, coronary score, main left or left anterior descending artery disease, coronary calcification, hypertension, or abnormal glucose tolerance test in patients with or without ectasia. A family history of coronary artery disease, diabetes mellitus, and hypertension did not separate the groups, neither did serum cholesterol level. The serum level of triglyceride was higher in the coronary ectasia group (p < 0.025). The location of infarction by electrocardiogram or abnormal left ventricular contractility was similar in both groups. Of 64 ectatic vessels, 34 (53 per cent) occurred in the right coronary, 16 (25 per cent) in the left anterior descending, and 14 (22 per cent) in the left circumflex artery. Thirty patients with ectasia and 26 in the control group underwent bypass surgery. Nineteen of the ectasia group and 17 of the control group had post-bypass graft angiograms. In the ectasia group, two out of 47 and, in the control group, five out of 41 grafts were closed. The postoperative course was similar in both groups. An 18 month (mean) follow-up of the 42 patients with coronary ectasia revealed no late deaths, whereas one death occurred in a control patient who did not have surgery. In conclusion, coronary ectasia is more common in the right coronary artery. The presence of coronary ectasia does not indicate more severe or widespread coronary disease than in controls. Short term follow-up of patients with ectasia, with or without bypass surgery, does not differ from control patients.     

Multiple coronary arteriosystemic fistulas

A 58 year old man presented with angina pectoris and no heart murmur. On selective coronary angiography, multiple coronary arteriosystemic fistulas involving all three major coronary arteries were found. This is the first such case reported. It is speculated that this vascular anomaly represents persistence of embryonic intertrabecular vessels that permit the coronary arteries to communicate with the left ventricular chamber through the Thebesian vessels.     

Clinical, hemodynamic and angiographic aspects of inferior and anterior myocardial infarctions in patients with angina pectoris

Clinical, hemodynamic and angiographic findings were reviewed in 82 patients with isolated inferior, 55 patients with isolated anterior and 27 with combined inferior and anterior myocardial infarction and were compared with findings in 100 patients without electrocardiographic evidence of a prior transmural myocardial infarction. All of the 264 patients were referred and evaluated because of angina pectoris and found, on selective coronary angiography, to have coronary artery disease. There was no significant difference in the ages of the patients in each group studied. A history of heart failure, audible gallops and cardiomegaly were more prevalent in the two groups with anterior infarction (isolated and combined with inferior infarction) than in the other two groups. The mean left ventricular hemodynamic measurements (end-diastolic pressure, end-diastolic volume and ejection fraction) in the groups of patients with a normal QRS or an isolated inferior myocardial infarction were not significantly different from those of patients with a normal left ventricle. Patients with isolated anterior myocardia infarction had abnormal end-diastolic pressure (68 percent), end-diastolic volume (51 percent) and ejection fraction (67 percent). Similarly, the group with multiple infarctions had abnormal hemodynamic measurements, with 81 percent having an abnormal ejection fraction. For the entire group of patients studied, an abnormal end-diastolic volume was always associated with an abnormal ejection fraction. Cardiomegaly on X-ray film was associated with an abnormal end-diastolic volume and ejection fraction. An abnormal contractile pattern (asynergy) was noted in 42 percent of the patients with a normal QRS; inferior asynergy was observed in 88 percent with inferior infarction, and anterior or apical asynergy, or both, was found in 90 percent with anterior infarction. All the patients with multiple infarctions had asynergy. The right coronary artery was significantly involved in 90 percent of the patients with inferior infarction, while all the patients with anterio infarction had significant disease of the left anterior descending artery. More than 80 percent of the patients with an infarction pattern on electrocardiogram had double or triple vessel disease, as compared with 68 percent of the patients with a normal QRS pattern. This study represents a select group of patients referred because of angina pectoris and cannot be extended to the asymptomatic patient with coronary artery disease. The observations made on these patients indicate that an anterior infarction (isolated or combined with inferior) in patients referred because of angina pectoris is accompanied by significant impairment of left ventricular function, whereas an inferior infarction (isolated), although accompanied by asynergy, is usually associated with normal hemodynamics. The electrocardiogram is not sensitive enough to predict reliably in the individual patient the extent and severity of the coronary artery disease.