The peak rate of systolic wall thickening (p +/- dTw/dt) in regions of the left ventricle (LV) was determined preoperatively by biplane roentgen videometry in 18 patients before and after sublingual administration of nitroglycerin (NTG) and 3-23 months (median 12) after aortocoronary bypass surgery. The regional LV response to NTG was a reliable predictor for postoperative improvement in regional wall dynamics after successful aortocoronary bypass grafting. The ejection fraction response to NTG or surgery will not predict the regional myocardial response to NTG or surgery, nor will the regional response predict the global response. Subendocardial myocardial infarction is another cause of unimproved regional myocardial function after NTG and aortocoronary bypass surgery.

The function of the cardiac sarcoplasmic reticulum (SR) and mitochondria was evaluated in left ventricular papillary muscle obtained from 47 patients with non-ischemic mitral valve disease and chronic heart failure (group I) and in right ventricular crista supraventricularis muscle obtained from 29 patients with congenital subvalvular pulmonic obstruction and right ventricular hypertrophy (group II). Heart muscle was removed approximately 15 min after establishment of cardiopulmonary bypass with hypothermia and about 4 min after first aortic cross-clamping. Cat cardiac tissues were used as a technical control. The SR and mitochondria were isolated by ultracentrifugation. 45Ca uptake (5 mm sodium oxalate) and binding were quantitated by Swinny Millipore filtration. Oxidative indices were defined polarographically by use of a vibrating platinum electrode. Compared with that of the non-failing patients (group II), the SR of the failing patients (group I) showed a significant depression of Ca uptake and binding at various ATP concentrations in both the absence and the presence of Ca-stabilizing EGTA. Calcium concentration necessary for half-maximal binding (KM) to SR approximated 1 × 10−7m in each group. There was no significant difference in the Ca-stimulated SR ATPase activity of groups I and II. ADP:O ratios and NADH-linked state 4 respiration were the same in both groups. NADH- and succinate-linked respiratory control and state 3 oxygen consumption rates were significantly lower in the failing group. The addition of ruthenium red, a specific inhibitor of mitochondrial Ca transport, led to a significant reduction of NADH- and succinate-linked state 4 respiration in group I, whereas no significant effect was elicited in group II. State 3 respiration rates were not depressed by ruthenium red. In the failing human papillary muscle, a significant reduction in Ca transfer across the SR membranes is, thus, demonstrated; it seems to be accompanied by a significant increase in Ca recycling across the mitochondrial membranes. No direct correlation among biochemical alterations, hemodynamic parameters, and duration of clinical cardiac failure was found.

The effect of atrial, ventricular, and atrioventricular (A-V) sequential pacing on cardiac output (CO) was evaluated in patients within 24 hours after cardiac surgery. In patients with normal sinus rhythm, ventricular pacing reduced CO by as much as 42% (average, 14%), whereas atrial and A-V sequential pacing at the same rate increased CO by averages of 13% and 19%, respectively. In patients with junctional rhythm, increase of the heart rate by ventricular pacing produced an increase in CO, however, and an additional 25% increase in CO could be obtained by atrial or A-V sequential pacing at the same rate. Atrial or A-V sequential pacing was superior to ventricular pacing at the same rate and they are the preferred methods for temporary carciac pacing in the postoperative period. In suitable cases elective A-V sequential pacing is an effective method for increasing CO after cardiac surgery.

The hemodynamic effects of atrioventricular (A-V) sequential pacing were assessed and compared with those of ventricular and of atrial pacing in 10 patients with and without heart block after cardiac surgery. Ventricular pacing alone was either hemodynamically detrimental or of no benefit in six of the eight patients who initially had sinus or accelerated junctional rhythms. Atrial pacing alone produced significant improvement in cardiac output in all patients who were not pacemaker-dependent. However, five of the eight patients with intact A-V conduction had further increases in cardiac output through A-V sequential pacing at shorter than intrinsic A-V intervals. Optimal A-V intervals for maximal cardiac output could be identified in all patients and varied widely. Significant changes in cardiac output occurred with relatively small deviations in the A-V interval. In selected patients after cardiac surgery, temporary A-V sequential pacing is a workable and valuable adjunctive form of hemodynamic support and is preferable to ventricular or atrial pacing.

Linear discriminant function analysis was used to test the independent prognostic value of nine variables in patients with coronary artery diseaase. For 68 medically treated patients who met the criteria for inclusion in the discriminant function analysis, the most reliable predictor of 2-year survival status was the left ventricular ejection fraction. The prognostic value of the ejection fraction was not improved by the addition of the number of vessels diseased. Comparisons of the survival of 130 medical and 284 surgical patients were made using subsets based on the ejection fraction. When the ejection fraction was greater than or equal to 50%, the probability of 4-year survival was high for both medical (91%) and surgical (96%) groups. When the ejection fraction was less than 25%, the probability of 2-year survival was low in both groups. However, for patients with ejection fraction 25 through 49%, the surgical patients had a better chance (P less than 0.05) for a 3-year survival (89%) than did medical patients (68%). This study emphasizes the prognostic significance of the left ventricular ejection fraction, which should be considered in any comparison of survival in medically and surgically treated patients.

The popliteal vessels rank second only to the external iliac system as the most frequent site of acquired arteriovenous communication. Direct trauma to the popliteal space is by far the most common cause, and surgical intervention is usually required to manage the defect. We present a recent illustrative case following meniscectomy. To our knowledge, the occurrence of an arteriovenous fistula complicating knee surgery has not been reported previously. This case outlines the potential value of B-mode ultrasound in diagnosis and the use of intraoperative angiography in assessing the adequacy of primary vascular reconstruction. Earlier experience of this vascular abnormality--six additional cases since 1941--is reviewed.

The initial experience with intra-aortic balloon assist (IABA) at the Mayo Clinic has been with 34 desperately ill individuals; 17 survived hospitalization. Hemodynamic improvement associated with institution of IABA can be documented. An unacceptably high complication rate (26%) has resulted in extensive modification in the technique of employing IABA. Concepts of patient selection and applications of IABA have evolved from this initial experience and from a review of the literature and have resulted in less reluctant use of this cardiac-assist modality.

Hemodynamics and blood gases were measured before and 15 minutes after small (10 mg/70 kg) doses of intravenously administered morphine in two groups of patients having open heart surgery. In one group, the study was undertaken after median sternotomy but before perfusion. The other group had been in the intensive care unit for approximately 1 hour. No changes were found in either group in cardiac index, atrial pressures, arterial pressure, or blood gas variables. However, mean systemic vascular resistance decreased from 41.5 to 35.4 after morphine was given postoperatively. Hence, hemodynamically, morphine is a safe drug if given in small doses for pain relief and sedation early after open heart surgery.

Dobutamine, a recently introduced derivative of dopamine, is reported to retain inotropic properties with less pronounced chronotropic and arrhythmogenic effects than isoproterenol. The drug was evaluated in two doses, 5 mug/kg/min and 10 mug/kg/min, in two groups of ten patients each, during emergence from cardiopulmonary bypass. A third group of five patients was studied similarly with isoproterenol, 0.02 mug/kg/min. Cardiac index increased 16 and 28 per cent eith the two doses of dobutamine, respectively, and 9 per cent with isoproterenol. Heart rate, in contrast, increased 6 and 15 per cent with dobutamine (not significant) and 44 per cent with isoproterenol (significant). Dobutamine seemed to associated with fewer arrhythmias than isoproterenol. It is concluded that dobutamine, 5-10 mug/kg/min, is suitable for use during emergence from cardiopulmonary bypass and may possess advantages over isoproterenol.

The peak rate of systolic wall thickening (pdTw/dt) in regions of the left ventricle was determined by biplane roentgen videometry in 60 patients before and a median of 14 mo after aorto-coronary bypass graft surgery. The left ventricular ejection fraction, stroke volume, and end-diastolic volume and pressure did not change significantly after surgery in the presence of patent or occluded grafts (P greater than 0.05). Statistically significant increases occurred in the peak rate of systolic wall thickening regions supplied by patent bypass grafts, and significant decreases occurred in regions with occluded grafts (P less than 0.01). Of 42 preoperatively hypokinetic regions (pdTw/dt greater than 0 less than 5.0 cm/s) supplied by a patent graft, 30 improved by an average of 2.6 cm/s after operation; 18 returned to normal. Failure of 24 hypokinetic regions to improve to normal was associated with myocardial infarction in 11 or with late postoperative graft blood flows of less than 60 ml/min measured by videodensitometry, in 10. All seven preoperatively akinetic (pdTw/dt=0) or dyskinetic (pdTw/dt less than 0) regions did not improve after the operation despite the fact that, in five of the seven, coronary bypass flows were over 60 ml/min. All eight preoperatively hypokinetic regions supplied by coronary artery graft flows of less than or equal 40 ml/min failed to improve to normal after operation. All nine preoperatively hypokinetic regions supplied by coronary artery graft flows of over 60 ml/min improved to normal after surgery. Late postoperative coronary artery bypass graft flows, the functional status of the myocardium, the status and distribution of the native coronary circulation, and decreased regional function elsewhere in the ventricle must all be considered when regional left ventricular function is interpreted.

In a prospective study of subendocardial myocardial infarction (SEI), 64 patients underwent coronary arteriography and left ventriculography early after their SEI. Of these 64 patients, 28 had saphenous vein grafting (SVG) performed within 3 months of SEI. The majority of this surgical group (24 of 28 patients) were operated on because of unstable angina following their SEI. Of these 28 patients, three suffered a perioperative myocardial infarction (10.7% incidence) and another patient died immediately postoperative (3.6% mortality). At a mean follow-up period of 16 months, 22 of these 28 patients (78%) were free of angina; in addition, there were no late deaths or recurrent myocardial infarctions in this surgical group. Therefore, SVG appears to improve the functional status of the majority of this group of patients with a complication rate at surgery comparable to that reported for unstable angina alone.

In 397 cases, serum glutamic oxaloacetic transaminase (GOT) and creatine phosphokinase (CPK) values were determined on the first, second, and third days after aorta-coronary artery saphenous vein bypass graft operations. Electrocardiographic (ECG) or vectorcardiographic (VCG) evidence of postoperative transmural infarction was found in 48 cases. Multivariate analysis indicated that GOT and CPK concentrations on day 1 had substantial discriminatory value regarding infarction. Discrimination by GOT values was not significantly improved by addition of CPK. Of the 61 cases positive by GOT values measured 1 day postoperatively (greater than 100 U. per liter; normal smaller than 24), 32 (52 percent) were negative by ECG or VCG; of the 336 cases negative by GOT, 19 (6 percent) were positive by ECG or VCG. GOT and CPK values increased with the number of vessels grafted and with the use of ventricular rather than atrial vents. Total serum enzyme values lack specificty in diagnosis of transmural infarction after the saphenous vein bypass operation.

The results in 578 patients who underwent a saphenous vein bypass graft operation (isolated SVBG) or a SVBG combined with other procedures (combined SVBG) from 1969 through 1972 were analyzed. The operative mortality rate was low (3 percent) for isolated SVBG but increased considerably for combined SVBG. The late mortality rate was also low (4 percent) for isolated SVBG and also increased markedly for combined SVBG. The operative mortality rate did not change in the group undergoing left ventricular aneurysmectomy or mitral valve surgery for postinfarction mitral insufficiency, whether or not SVBG was used; however, late results were better in both groups when SVBG was performed. Among all groups, patients with postinfarction mitral insufficiency or rheumatic mitral incompetence associated with coronary artery disease had the poorest outcome. Despite the operative and late deaths, patients undergoing SVBG with aortic valve replacement showed excellent results in the group of survivors.

Review of 1,684 cases of isolated aortic or mitral valve replacement with a Starr-Edwards prosthesis demonstrated that the procedure provides improved life expectancy over that found in the natural history of valvular heart disease. Further improvement in results depends on continued reduction in operative and late mortality and in the incidence of thromboembolism. Advanced preoperative functional class, atrial or ventricular enlargement, a history of prior heart surgery, advanced age at operation and untreated valvular disease were among the factors related to increased early or late mortality. The data suggest that adequate anticoagulation, earlier performance of valve replacement and more complete repair of valvular dysfunction may increase survival rates.

In a series of 500 consecutive patients undergoing aorta-coronary artery saphenous vein bypass surgery, operative mortality was 2.5% (1% with one-vessel disease, 2% with two-vessel disease, and 3% with three-vessel disease). Transmural myocardial infarction occurred within 30 days after operation in 67 cases (13%) and caused 10 of the 16 deaths in that period. Among 484 patients followed 1 to 58 months (median, 26 months), there have been 20 deaths. Of the 464 survivors, 65% had complete relief of angina, 24% were improved, and 11% were unimproved. In 162 patients who underwent postoperative graft angiography between 1 and 42 months after surgery, a strong positive relationship existed between clinical response and completeness of myocardial revascularization as defined by the presence of a patent graft to all major coronary arteries with greater than 50% stenosis. A similar relationship was found between postoperative multistage treadmill exercise response and completeness of myocardial revascularization. Thus, 82% of patients completely revascularized were asymptomatic at the time of postoperative graft visualization, and 91% had a negative treadmill exercise response.