Joginder N. Bhayana

Partial Left Ventriculectomy to Treat End-Stage Heart Disease☆

BACKGROUND It is reasoned that reducing left ventricular diameter (Laplaces law) in patients with dilated cardiomyopathy, will improve ventricular function. METHODS Partial left ventriculectomy was performed in 120 patients with end-stage dilated cardiomyopathies of varying causes. Most patients were in New York Heart Association functional class IV. The procedure consisted of removal of a wedge of left ventricular muscle from the apex to the base of the heart. Depending on the distance between the two papillary muscles, the mitral valve apparatus was either preserved, repaired, or replaced with a tissue prosthesis. RESULTS The 30-day mortality was 22% and the 2-year survival was 55%. Although 10% of surviving patients showed no improvement in New York Heart Association functional class, most of the surviving patients were in either class I (57%) or II (33.3%), and the others were in class III and IV. CONCLUSIONS Partial left ventriculectomy can be used to treat end-stage dilated cardiomyopathy. Further studies and a longer follow-up period are needed to fully assess the effects of this procedure.

Perioperative Myocardial Infarction: A Diagnostic Dilemma

Patients undergoing coronary bypass grafting were studied for incidence of perioperative myocardial infarction (MI) using three modalities: serial electrocardiograms (ECG), serial creatine phosphokinase isoenzymes (MB-CPK), and serial technetium 99m-labeled pyrophosphate scans. A definite perioperative MI was diagnosed if the results were positive in two of the three variables studied. The perioperative infarction rate for the entire group was 8%. The operative mortality was 2.9%. Seven of 8 perioperative MIs were diagnosed by the use of scanning alone. The combination of isoenzyme and ECG analysis diagnosed 5 of 8 perioperative MIs. The MB-CPK and ECG studies were associated with a higher incidence of false-positive diagnoses than myocardial scanning. Patients with perioperative MI had a benign clinical course. Justification for performing three routine 99mTc-pyrophosphate scans on all patients undergoing aortocoronary bypass operation is still to be determined.

Use of duplex imaging to assess suitability of the internal mammary artery for coronary artery surgery

The internal mammary artery is the preferred conduit for coronary artery surgery. To determine the role, if any, of preoperative duplex imaging in assessing the suitability of this vessel, preoperative noninvasive measurements of internal mammary artery diameter and blood flow were performed in 243 patients. The left internal mammary artery was insonated through the third intercostal space by use of duplex scanner (5.0 MHz probe) before coronary artery surgery. Internal mammary artery diameter (millimeters), peak systolic velocity (centimeters/second), and mean velocity (centimeters/second) were measured, and internal mammary artery flow was calculated from velocity and cross-sectional area. In 45 of these patients the internal mammary artery diameter also was measured during surgery with a sterile caliper, and blood was collected for 30 seconds from the transected internal mammary artery to measure flow. These findings were compared to the preoperative values. In 243 patients the mean internal mammary artery diameter was 2.34 +/- 0.03 mm, and mean peak systolic blood flow was 226.7 +/- 6.3 ml/min. In the 45 patients in whom intraoperative measurements were obtained, preoperative mean internal mammary artery diameter was 2.39 +/- 0.05 mm and was not significantly different from the intraoperative mean internal mammary artery diameter of 2.36 +/- 0.04 mm. Preoperative peak systolic flow was 231.3 +/- 8.1 ml/min, and mean flow was 110.3 +/- 7.1 ml/min; intraoperative flow measured 136 +/- 3.6 ml/min. Noninvasive determinations correlated with operative findings for internal mammary artery diameter (r = 0.87) (p less than 0.05), peak systolic blood flow (r = 0.70) (p less than 0.05), and mean blood flow (r = 0.60) (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Pulmonary resection combined with cardiac operations

Surgical management of patients with concomitant critical cardiac disease and resectable lung lesions is controversial. During a 7-year period (1982 to 1988), 21 patients underwent combined cardiac and pulmonary operations. Patients had cardiac symptoms only; the lung lesions were found on preoperative chest roentgenograms. The pathological diagnosis was established in only 2 of the patients before operation. All underwent concurrent pulmonary resection during cardiac operations requiring extracorporeal circulation. The pulmonary operations included 17 wedge resections and four lobectomies. The final diagnoses in 8 patients with stage I non-small cell lung cancer included epidermoid carcinoma (4), adenocarcinoma (3), and bronchoalveolar carcinoma (1). Postoperatively, 1 patient required a permanent pacemaker and 1 patient died. The actuarial survival at 5 years for all patients who underwent combined procedures was 95%. The 5-year survival for the 8 patients with lung cancer was 88% compared with 100% for those with benign pulmonary pathology (p = 0.172). This experience suggests that combining pulmonary resection with cardiac operations is safe and offers a favorable prognosis to a select group of patients.

Circumferential Intimal Tear Causing Obstruction of the Aortic Arch: An Unusual Complication of Aortic Dissection

A 66-year-old man was first seen because of occlusive disease of the aortic arch vessels secondary to a Type I aortic dissection. At operation, circumferential detachment of the intima was found with intussusception of this flap into the descending aorta causing obliteration of the arch vessels. There has been only one previous report of circumferential intimal intussusception complicating aortic dissection.

Traumatic Left Ventricular Papillary Muscle Rupture: The Role of Transesophageal Echocardiography in Diagnosis and Surgical Management

We report a case of left ventricular posteromedial papillary muscle rupture caused by blunt chest trauma. Transesophageal echocardiography was used to establish the diagnosis and to assist with surgical repair of the mitral valve apparatus. Echocardiographic findings of the acutely ruptured papillary muscle are reviewed.

Cardioplegia delivery by combined aortic root and coronary sinus perfusion

Retrograde coronary sinus perfusion for the administration of cardioplegic solutions has recently been the subject of renewed interest. A method is described for the administration of bolus antegrade cardioplegia followed by continuous retrograde coronary sinus perfusion, particularly for patients with left main artery disease, left main equivalent, or aortic root/aortic valve disease. Advantages of the technique are discussed, as well as its limitations and its use for myocardial preservation in heart transplantation.

Perioperative Protection of the Myocardium in Patients with Impaired Ventricular Function

Seventeen patients with poor ventricular function and severe coronary artery obstruction were operated on employing hypothermic potassium cardioplegic solution for myocardial preservation. Preoperatively and postoperatively, serial hemodynamics, electrocardiograms (ECG), MB-CPK studies, and technetium pyrophosphate scans were obtained for all patients. All ECGs and scans were negative for perioperative infarction. Peak MB-CPK levels were 40 +/- 25 units per liter. Two patients had MB-CPK levels suggestive of perioperative myocardial infarction. The preoperative cardiac index was 2.8 +/- 0.8 L/min/m2 and remained the same in the perioperative period. Stroke work index and total peripheral resistance were within normal range and remained constant throughout the period of study. Three patients required epinephrine (0.5 micrograms per minute) during the first 6 hours postoperatively, and in 2 patients an intraaortic balloon was inserted prophylactically and removed on the second postoperative day. Good myocardial preservation can be achieved in patients with severe coronary artery obstruction and preexisting left ventricular dysfunction using hypothermic potassium cardioplegic solution.

Improved Cardiovascular Hemodynamics with Atrioventricular Sequential Pacing Compared with Ventricular Demand Pacing

To determine the advantages of atrioventricular (AV) sequential pacing over ventricular demand pacing, paired cardiovascular hemodynamic studies were performed in each pacing mode at a constant heart rate. The paired studies included determination of ejection fraction (EF) by echocardiography and gated blood pool radionuclide scanning, and of cardiac output (CO) by the indicator-dilution method. There was no significant difference in EF with either pacing mode. Determined by echocardiography, EF with AV sequential pacing was 57% compared with 56% with ventricular demand pacing; by the gated blood pool method, EF with AV sequential pacing was 58% compared with 57% in the ventricular mode. Significant improvement with AV sequential pacing was seen in CO (4.75 L/min from 3.75 L/min; p less than 0.01); stroke volume (58 ml from 48 ml; p less than 0.02); arteriovenous oxygen content difference (4.9 vol% from 5.6 vol%; p less than 0.01); total peripheral resistance (1,724 dynes sec cm-5 from 2,025 dynes sec cm-5; p less than 0.01); and cardiac contractility, as reflected by mixing time (6.9 seconds from 8.0 seconds; p less than 0.02). No significant changes were noted in mean arterial or atrial pressure or in systemic oxygen consumption. In a second group of 6 patients, similar paired studies were done in AV sequential pacing modes before and after therapeutic reduction of total peripheral resistance. A significant increase in CO (43%) was observed following reduction in total peripheral resistance. We conclude that AV sequential pacing improves CO more effectively than ventricular demand pacing. Cardiac output can be further enhanced in patients with congestive heart failure by pretreatment with agents to reduce total peripheral resistance.

Instrumentation for the Follow-Up of Pacemade Patients.: Telephone Transmission of the Electrocardiogram and Self-Check by the Patient on Pacemaker Function and Capture

Logic circuitry has been added to an electrocardiogram telephone transmitter. It processes the electrocardiogram and permits frequent self‐checks by the patient on rate, capture and sensing function of an implanted demand pulse generator system. Correct function is communicated to the patient by a green light Malfunction with regard to any of these parameters produces an irreversible yellow light signaling the patient to contact his physician. The self‐check is reassuring to the patient during intervals between visits to the physicians office or a specialized clinic. The system, at present, is applicable only to demand pulse generators with a high magnet lest rate (90 ppm or higher) which assures capture in virtually all patients. This and other limitations are discussed. Their incidence is low, some can be remedied and in the majority of patients they do not impair the clinical usefulness of the system. (PACE, Vol. 2, May‐June 1979)