Ventricular apical vents and postoperative focal contraction abnormalities in patients undergoing coronary artery bypass surgery

Ventriculograms made 9-15 months after surgery in 48 patients with normal preoperative apical contraction were reviewed to determine the influence of apical venting on apical wall motion in patients undergoing coronary bypass surgery. After interpretation of postoperative apical wall motion, the patients were subdivided into two groups. One group consisted of 34 patients who were vented by inserting a catheter through the apex of the left ventricle and the second group included 14 patients in whom no transventricular vent was made. The two groups were similar clinically and hemodynamically before surgery, and the surgical procedures were similar with the exception of vent site. Following surgery, incidences of graft patency and antegrade flow to the apex were also similar. Nineteen (56%) patients in the apically vented group had apical dyskinesia or akinesia observed on the postoperative ventriculogram while none of the patients who were not apically vented had these findings. None of the patients with apical dyskinesia or akinesia had congestive heart failure following surgery. The postoperative ventriculograms of 12 patients with mitral stenosis who underwent valvulotomy by inserting a Tubbs dilator through the apex were also analyzed. Only one patient (8.5%) had apical dyskinesia or akinesia. Since the patients with mitral stenosis probably did not have significant coronary artery disease, it is possible that the combination of the apical vent and ischemic heart disease was responsible for the focal contraction abnormalities observed.

Diagnostic and prognostic significance of electrocardiographic and CPK isoenzyme changes following coronary bypass surgery: correlation with findings at one year

The incidence of ECG (14 per cent) indication of acute myocardial infarction complicating coronary artery bypass surgery is documented, corroborating the findings of prior series. An additional 32 per cent of patients had appearance of myocardial specific CPK-MB in serum during the immediate postoperative period. All patients surviving to 1 year following surgery (93 of 103) were asked to return for repeat cardiac catheterization to determine the presence and extent of interim ventricular contraction abnormalities. Sixty-five (70 per cent) of the group returned for evaluation. Preoperative and 1 year postoperative left ventriculograms were compared to determine if new contraction abnormalities would confirm the specificity of perioperative QRS and isoenzyme changes, and if the absence of new abnormalities would confirm their sensitivity. The majority of patients (65 per cent) had new areas of asynergy. However, 73 per cent of these were confined to the apex and thus could have been produced by the vent employed during cardiopulmonary bypass. QRS changes were 100 per cent specific and CPK-MB appearance was 78 per cent specific but they were only 20 and 54 per cent sensitive, respectively. Indeed, 46 per cent of those with new asynergy which was non apical had neither QRS change nor CPK-MB appearance. Thus QRS changes were always--and CPK-MB appearance was usually--associated with new asynergy but, in addition, many patients with no perioperative indication of infarction developed new areas of left ventricular contraction abnormality within the first postoperative year.

Aortocoronary bypass surgery: Correlation of angiographic symptomatic and functional improvement at 1 year

Angiographic changes in the coronary circulation were evaluated in 60 patients 1 year after aortocoronary bypass surgery, and their relation to the postoperative clinical status was examined. Of 124 grafts implanted, 26 were closed, 7 stenotic and 91 (74 percent) patent at 1 year. Progression of occlusive disease occurred in 21 of 57 (37 percent) nongrafted and 78 of 123 (63 percent) grafted vessels. On the basis of location and severity of progression, significant lesions bypassed and patency of grafts, postoperative coronary perfusion was considered optimal in 16 patients (Group I), better in 24 (Group III). Complete freedom from chest pain or lessening of pain (improvement by two New York Heart Association functional classes) occurred in 88 and 79 percent of patients in Group III. Positive preoperative treadmill stress tests became negative after surgery in five of six patients in Group I, five of eight in Grojp II and three of eight in Group III. This study demonstrates that when progression of disease, graft patency and extent of revasculariztion are considered in combination, the postoperative angiographic status of the coronary circulation correlates well with clinical improvement at 1 year. These findings support the hypothesis that improved blood supply to ischemic myocardium is a major factor contributing to relief of angina pectoris after saphenous vein bypass surgery.

The hemodynamic simulation of mitral regurgitation in ventricular septal defect after myocardial infarction

The development of a ventricular septal defect (VSD) following myocardial infarction is an uncommon complication which clinically can be confused with mitral insufficiency due to infarction of a papillary muscle. The clinical and hemodynamic records of six patients with documented acute VSD secondary to myocardial infarction were analyzed to determine which descriptors would be of value in clinically separating these two entities. All six of our patients had a right heart catheterization showing an oxygen step-up consistent with a VSD, and five had a large pulmonary wedge V wave suggesting concomitant mitral insufficiency. The echocardiogram showed only nonspecific chamber enlargement. Since these patients were being considered for open heart surgery to close the VSD, left and right cardiac catheterization including selective coronary arteriography was done. Despite large V waves being present in the pulmonary wedge and/or left atrial pressure tracing in five of the six patients, no mitral insufficiency was present on the left ventricular cineangiograms. It is concluded that a large pulmonary wedge and/or left atrial V wave does not necessarily indicate mitral insufficiency. Since both a VSD and mitral insufficiency are surgically correctable, patients who develop new holosystolic murmurs following myocardial infarction should have complete right and left heart catheterizations with LV angiography for accurate diagnosis if surgical correction of the lesion is contemplated.

Sudden death due to coronary artery disease. A clinical, hemodynamic, and angiographic profile

The authors followed 536 medically managed patients with angiographically documented coronary artery disease for up to 4 years, and examined antemortem clinical, anatomical, and hemodynamic characteristics of the 29 patients who died suddenly during the follow-up period. These patients are compared in terms of hemodynamic characteristics to those who survived and those who died non-suddenly of coronary heart disease. Of the 29 patients who died suddenly, more than 80% had evidence of moderate to severe impairment of myocardial function many months prior to death. Only a single patient had the combination of relatively mild coronary artery disease and normal ventricular function. This single patient would be the ultimate target of a program designed to prevent sudden death. However, it has been necessary to follow 536 patients with angiographically documented coronary artery disease in order to find this one potential benefactor of sudden death prophylaxis. This study demonstrates that there are patients with coronary artery disease who die suddenly, despite relatively mild disease; however, these patients appear to represent only a small proportion of all sudden deaths.

Comparison of angiographic and postmortem findings in patients with coronary artery disease

The accuracy of coronary cineangiography in predicting the degree of stenosis in coronary arteries was evaluated by comparing autopsy and premortem cineangiographic findings in 25 patients. Coronary cineangiograms and autopsy specimens were reviewed independently by two cardiologists and two pathologists. Identical diagrams dividing the cononary arteries into 12 segments were used by both groups to record the location and degree of stenosis observed. Cineangiographic findings were in agreement with pathologic findings (less than 25 percent difference in cross-sectional luminal area) in 178 (79 percent) of the 226 segments examined, but overestimated the degree of stenosis in 13 (6 percent) and underestimated it in 34 (15 percent). Thus, cineangiography appears to be a reliable tool in evaluating coronary artery disease. When diagnostic errors are made, they are usually underestimations of the degree of disease; common causes of error are circumferential stenosis, eccentric lesions, obstruction of view by artifical valves and poor opacification due to severe proximal stenosis.

The significance of coronary calcification detected by fluoroscopy. A report of 360 patients

Cardiac fluoroscopy to detect coronary calcification was performed on 360 patients before undergoing coronary arteriography for proven or suspected coronary artery disease. Among the 154 patients in whom coronary calcification was identified, 97% had significant coronary disease angiographically (≧ 70% stenosis). In this group, the distribution of one, two, and three vessel coronary disease was 9%, 25%, and 66% respectively. The prevalence of coronary calcification increased with age and severity of coronary disease, but no difference in males versus females was demonstrable. The angiographic severity of coronary disease increased with multiple vessel calcification; three vessel disease occurred in 45%, 66%, and 82% of patients with one, two, and three vessel calcification, respectively. Patients with hyperlipidemia or hypertension had no significant difference in the prevalence of coronary calcification. Among the 267 patients with significant coronary lesions, 56% had calcification detected by fluoroscopy.

Five of the 93 patients with no significant coronary disease angiographically had coronary calcification fluoroscopically. Four of the five had a prior history of myocardial infarction, and two showed asynergy on left ventriculography.

This study demonstrates that cardiac fluoroscopy is a valuable procedure for detecting significant coronary artery disease since this highly specific test is easily performed, inexpensive, noninvasive, and widely applicable for screening large patient populations.

The nature of treatment selection in coronary artery disease. Experience with medical and surgical treatment of a chronic disease

This report presents our experience with the medical and surgical management of patients with coronary heart disease and uses this experience to document the role of a computerized medical information system in the long-term management of patients with a chronic disease. Of 781 consecutively evaluated patients, 402 were treated medically and 379 were treated with aortocoronary bypass surgery. At two years post-zero time, more than twice as many surgical survivors were pain free, but the survival was the same in the medical (83%) and surgical (85%) cohorts. The medically and surgically treated patients were compared with respect to 89 baseline characteristics. The cohorts were remarkably similar. Correction for baseline inequalities did not affect the fact that two-year survival was the same in both cohorts. One subgroup was identified in which surgically treated patients had a higher two-year survival. Other subgroups were identified in which therapy did not appear to affect two-year survival.

Graded exercise stress tests in angiographically documented coronary artery disease

Graded exercise stress tests performed on 650 consecutive patients with proven or suspected coronary disease undergoing evaluation by cardiac catheterization were correlated with clinical, hemodynamic, and angiographic findings. Among 451 patients with significant coronary stenosis, 332 (74%) had interpretable stress tests and 65% of these were positive (sensitivity). The rate of "false positives" was 8%.

The clinical syndrome of typical angina identified significant coronary disease in 89% of the patients, and 58% of that group had a positive exercise test defined by objective electrocardiographic criteria.

Patients were not eliminated from this study because of recent digitalis ingestion. Although a higher frequency of uninterpretable exercise tests was found in this group (40%), the test results reflected more severe coronary disease. None of the patients with "false positive" tests were taking digitalis. It is concluded that recent digitalis ingestion should not be considered a contraindication for exercise stress testing.

Among the patients with interpretable exercise tests, the angiographic severity of coronary artery disease correlates strongly with the frequency of positive tests (40%, 66%, and 76%, with 70% or greater occlusion of one, two or three vessels respectively). Left main coronary stenosis of 70% or greater was associated with more severe ST segment changes, inability to achieve target heart rate during stress, and a lower maximum heart rate during exercise. The angiographic occurrence of collateral vessels was related to the extent of coronary disease and was associated with a higher percentage of positive exercise tests; no protective effect of collateral circulation could be demonstrated. Patients with abnormal resting hemodynamics or left ventricular asynergy had no significant difference in the frequency of positive tests after adjustment for the angiographic severity of disease.

Cefoxitin, a semisynthetic cephamycin antibiotic: in vivo evaluation

Cefoxitin, 3-carbamoyloxymethyl-7-alpha-methoxy-7-[2-(2-thienyl)acetamido]-3-cephem-4- carboxylic acid, a semisynthetic cephamycin antibiotic shown to have broad-spectrum activity in vitro, is active also in vivo against a wide variety of bacteria including penicillin-resistant staphylococci. It is, however, particularly effective against gram-negative organisms including strains of indole-positive Proteus against which cephalothin and cephaloridine are ineffective. When cefoxitin is given subcutaneously, concentrations in mouse blood, urine, and other tissues are higher than those seen for cephalothin. Higher concentrations in the blood and greater therapeutic efficacy are achieved with cefoxitin when it is given with probenecid. For this reason it is believed that cefoxitin is excreted mainly by way of the renal tubules. The data indicate that cefoxitin has potential as a therapeutically useful antibiotic.

Letter: Ventricular septal defect and mitral regurgitation secondary to myocardial infarction

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Exercise stress testing in evaluation of aortocoronary bypass surgery. Report of 123 patients

Graded exercise treadmill tests (ET) were performed on 123 patients who had undergone aortocoronary bypass surgery. All had angina preoperatively (preop) and 77% were in Class III or IV for angina. Postoperatively (postop), 68% were free of angina. Eighty-three patients had ST-segment changes of 0.1 mV or greater during stress preop (positive), 38 of which (46%) converted to electrocardiographically negative postop. Among the 30 patients (36%) remaining positive during stress postop, 19 (63%) were angina free despite ST-segment depression during stress. Among the 17 patients with negative ET preop, there were no conversions to positive postop. Twenty-three patients had undetermined ET preop; 13 remained undetermined postop, 4 were positive and 6 were negative. Patients experiencing a perioperative myocardial infarction more frequently had a negative postop ET. Among 27 selected patients undergoing postop angiography, there was good correlation between relief of symptoms and successful myocardial revascularization.

This study demonstrates that dramatic improvement in angina after aortocoronary bypass surgery can be objectively substantiated in most patients. Subjective symptoms of angina are frequently absent during myocardial ischemia postop, emphasizing the importance of exercise testing in objective evaluation of surgical results.

Cephamycins, a new family of beta-lactam antibiotics. IV. In vivo studies

Cephamycin A was found to be more active in vivo than cephamycin B. In comparison with cephamycin C, cephamycin A was more active against gram-positive organisms but less active against gram-negative organisms. Given subcutaneously, cephamycin C had good in vivo gram-negative activity, comparing favorably with cephalothin and cephaloridine against cephalosporin-susceptible organisms. In general, against the gram-negative organisms, it was more active than cephalothin or cephalosporin C and about as active as cephaloridine. In addition, cephamycin C protected mice against beta-lactamase-producing Proteus cultures, including clinically isolated strains. The compound is remarkably nontoxic. Cephamycin C was detected in the serum and recovered from the urine of treated mice to about the same extent as cephaloridine. Like cephaloridine and cephalosporin C, cephamycin C must be excreted mainly by glomerular filtration, because the use of probenecid did not enhance the therapeutic effectiveness nor concentrations of these agents in the sera of treated mice.

Fusion of the left aortic cusp to the aoic wall with occlusion of the left coronary ostium, and aortic stenosis and insufficiency

The case of a 16-year-old girl with a unique anomaly of the coronary arterial tree is presented. This report concerns the first known case of isolated adherence of the left coronary aortic valve cusp to the aortic wall. This produced total obstruction of the left coronary artery ostium, angina pectoris, syncope, aortic stenosis, and aortic insufficiency. Freeing the adherent cusp from the aortic wall restored patency of the left coronary artery, relieved the aortic insufficiency, and resulted in disappearance of the angina pectoris and syncope. This case adds to the growing spectrum of nonatherosclerotic coronary abnormalities which are capable of producing myocardial ischemia.