Christian Olin

CLINICAL AND HAEMODYNAMIC RESULTS OF AORTIC VALVE REPLACEMENT WITH THE BJORK-SHILEY TILTING DISC VALVE PROSTHESIS

One hundred and one patients with aortic valve disease, aortic stenosis 29 patients, aortic insufficiency 29 patients and combined lesions in 43 patients, underwent valve replacement with the Bjork-Shiley tilting disc prosthesis. Early and late mortality rate 8% and 3% respectively. Six patients died in heart failure, 2 after a myocardial infarction, one due to cardiomyopathy, one of septicaemia and one due to carcinoma of the stomach. No thrombo-embolic complications were encountered.Fifty-seven of the patients were subjected to a follow-up study 6 to 8 months after surgery, including right and left heart catheterization. All these 57 patients were subjectively improved by the operation and 30/57 were considered to be in an excellent clinical condition.The heart volume in supine decreased on average 20% after operation. The exercise tolerance (Wmax) increased in 24/57 patients. There were marked decreases in left ventricular systolic and end diastolic pressures. Pulmonary arterial and right heart pressur...

Are electrocardiographic Q-wave criteria reliable for diagnosis of perioperative myocardial infarction after coronary surgery?

OBJECTIVE A major assumption in cardiovascular medicine is that Q-waves on the electrocardiogram indicate major myocardial tissue damage. The appearance of a new Q-wave has therefore been considered the most reliable criterion for diagnosis of perioperative myocardial infarction (PMI) in cardiac surgery. In a study, originally intended to evaluate troponin-T as a marker of PMI, analysis of our data aroused the need to address the reliability of Q-wave criteria for diagnosis of PMI. METHODS In 302 consecutive patients undergoing coronary surgery, Q-wave and other electrocardiogram (ECG) criteria were compared with biochemical markers of myocardial injury and the postoperative course. All ECGs were analysed by a cardiologist blinded to the biochemical analyses and the clinical course. RESULTS The incidence of positive Q-wave criteria was 8.1%. Combined biochemical (CK-MB > or = 70 microg/l) and Q-wave criteria were found in 1.0%. Patients with new Q-waves did not have CK-MB or troponin-T levels significantly different from those without Q-waves. More than 25% of the Q-waves were associated with plasma troponin-T below the reference level (< 0.2 microg/l) on the fourth postoperative day. Q-wave criteria alone did not influence the postoperative course. In contrast, biochemical markers correlated with clinical outcome. CONCLUSIONS The majority of Q-waves appearing after coronary surgery were not associated with major myocardial tissue damage, and according to troponin-T one-fourth of the Q-waves were not associated with myocardial necrosis. Furthermore, the appearance of Q-waves had little influence on short term clinical outcome. Therefore, the use of Q-wave criteria as the gold standard for diagnosis of PMI may have to be questioned.

Septicaemia and Endocarditis — Uncommon But Serious Complications in Connection with Permanent Cardiac Pacing

Between 1971 and 1978 septicaemia was observed in 14 patients undergoing permanent pacemaker treatment. The causative microorganisms were: S. aureus (9), S. epidermidis (3), alfa-haemolytic streptococci + P. morganii (1), enterococci (1). In 4 patients, a mural endocarditis of the right atrial wall surrounding the electrode was found at operation or autopsy. The interval between the preceding pacemaker operation and onset of septicaemia varied between 2 days and 23 months (median 2 months). In 5 patients, the last operation before septicaemia was performed because of local infection in the pacemaker pocket or along the electrode. A probable portal of entry was found in 11 patients. The electrode was the origin in 8, the pacemaker pocket in one, and a focus outside the pacemaker system in 2. Of the 6 patients treated with antibiotics alone, 3 were cured, 2 died and one is still on treatment. Eight patients underwent various surgical procedures in addition to the antibiotic treatment. In 4 the electrode was completely removed. In 2 of them cardiotomy during extracorporeal circulation had to be used. All of these patients were cured. In 3 the pacemaker system was partially extracted. Only one of them was cured, one developed osteomyelitis and one died. Based on our experience, we now recommend that all foreign material should be removed, if possible, in the presence of septicaemia and/or endocarditis, and that parenteral antibiotic treatment should be given for at least 6 weeks.

Pulsatile flow Studies of Prosthetic Aortic Valves

A pulse duplicator system, used for studying prosthetic heart valves, is described. It provides a pulsatile flow resembling that produced by the heart, and permits a quantitative estimation of fluid flow resistance, regurgitation and energy loss in the valves. A technique for visualization of flow pattern is presented. The hydrodynamic performance of five prosthetic aortic valves, Starr-Edwards, Smeloff-Cutter, Kay-Shiley, Wada-Cutter and Bjork-Shiley, were studied in the pulse duplicator and compared on the basis of their external (tissue) diameters. For a given tissue diameter, the Bjork-Shiley valve had the best performance, resulting in a significantly lower flow resistance and energy loss than in the other prostheses investigated. All valves had acceptably low degrees of regurgitation with the exception of the Wada-Cutter prosthesis (16 to 20% of stroke volume). Flow visualization demonstrated a more or less turbulent flow pattern in all the valves with the exception of the Bjork-Shiley valve. In thi...

Myocardial Protection During Aortic Valve Replacement: Cardiac Metabolism and Enzyme Release Following Continuous Blood Cardioplegia

Cardiac metabolism following hypothermic potassium cardioplegia with blood as cardioplegia vehicle was studied in two groups of patients undergoing aortic valve replacement. In 15 patients, blood was given as single dose infusion (single dose group) and in 18 patients the same initial bolus was followed by a continuous perfusion (25-30 ml/min) with modified blood from the heart-lung machine (continuous blood group). Simultaneous samples were drawn from arterial and coronary sinus blood before and during the first 60 min after cardioplegia. In the continuous blood group, samples were also drawn during the period of cardioplegic perfusion. The samples were analyzed for PO 2, O2-saturation and content, PCO2, pH, lactate, pyruvate, glucose, potassium, myoglobin, creatine kinase (CK), its isoenzyme MB, and aspartate aminotransferase (ASAT). In addition myoglobin and enzymes were followed in peripheral venous blood for 24 hours. Myocardial biopsies were taken from the left ventricle at the beginning and end of cardioplegia and analyzed for adenosine triphosphate (ATP), creatine (C) and creatinephosphate (CP). The pattern of metabolic changes after cardioplegia was similar in both groups with decreased myocardial oxygen extraction, marked lactate and potassium release, increased glucose uptake and significant enzyme and myoglobin release. However, the degree of changes was significantly smaller in the continuous blood group. The myocardial biopsies also showed significantly less ATP and CP decrease in the continuous blood group, suggesting, together with the other metabolic results, that the myocardial protection afforded by continuous blood cardioplegia was superior to that of the single dose group. Furthermore, continuous perfusion permitted easy control of myocardial temperature during the period of aortic cross-clamping.

Primary idiopathic chylopericardium—a case report and review of the literature

Primary idiopathic chylopericardium is a rare entity with obscure etiology. In recent years, a few reports have been published where the lymphatic leak and fistula were identified by combined lymphangiography and computed tomography or intraoperative thoracic ductogram. Here we report a case occurring in a previously healthy 51 year old woman, to our knowledge the first case described in Scandinavia. She presented with cough and dyspnea of about 1 year duration. Chest X-ray demonstrated enlargement of the cardiac silhouette. Echocardiography revealed pericardial effusion and at puncture pericardiocentecis 760 ml of chylous fluid was evacuated. There was no history of trauma, infection or neoplasm. She underwent extensive investigations but no apparent cause of the chylous effusion could be determined. Conservative treatment with pericardial drainage and low fat (medium chain triglyceride) diet failed. The patient was cured by surgical ligature of the thoracic duct and partial pericardectomy through a left anterolateral thoracotomy. At 12 months post operation she was doing well and echocardiography did not reveal any signs of recurrence. A brief review of the literature is presented.

Antibiotic Prophylaxis in Pacemaker Surgery—a Prospective Study

To evaluate the effect of antibiotic prophylaxis in pacemaker surgery, 100 patients were randomly assigned to a prophylaxis group receiving cloxacillin or to a control group with no antibiotics. Cloxacillin was given intravenously (2 g) 2 hours before operation, followed by 1 g every 6 hours for 2 days and the same dose perorally for 8 more days postoperatively. Adequate plasma concentrations were obtained in all patients. The follow-up time was 1-43 months. The infection rate was 2% (1/50) in the prophylaxis group and 14% (7/50) in the control group (p less than 0.05). The interval from operation to manifest infection was 9-35 days. In the control group the causal microorganism was Staphylococcus aureus in two patients, Staphylococcus epidermidis in two and unknown in three patients. In the only patient with infection in the prophylaxis group, a methicillin-resistant S. epidermidis was isolated. Infection was initially localized to the pacemaker pocket in seven patients, but septicemia developed in one of them and endocarditis in another. In one patient septicemia appeared initially, without local signs of infection. This study suggests that cloxacillin prophylaxis is of value in routine pacemaker surgery.

Serum Enzymes with Special Reference to CK-MB Following Coronary Bypass Surgery

In a consecutive series of 25 coronary bypass operations, the postoperative serum activity levels of total creatine kinase (CK) and its more heart-specific isoenzyme CK-MB were examined and related to the levels of aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT) and thermostable lactate dehydrogenase (LD-T), to electrocardiographic (ECG) findings and to surgical characteristics. Detectable CK-MB activity was found in all patients, usually appearing while the operation was still in progress. Peak CK-MB occurred earlier than peak total CK. There was no ECG evidence of myocardial infarction in any patient. The degree of postoperative CK-MB elevation, however, correlated to the duration of extracorporeal circulation (ECC) and aortic cross-clamping (AC). After 120 min of ECC and 70 min of AC, release of CK-MB, as well as of the other enzymes studied, increased considerably. There was a significant correlation between high CK-MB activity and high early postoperative activities of total CK, ASAT and LD-T. When CK-MB determinations are not available, ASAT is preferable to total CK or LD-T in the early evaluation of operative myocardial injury. From the fourth postoperative day, only LD-T is informative in this respect; a second rise of ASAT and ALAT is probably of hepatic origin.

Myocardial Protection During Aortic Valve Replacement. Cardiac Metabolism and Enzyme Release Following Hypothermic Cardioplegia

Cardiac metabolism following hypothermic potassium cardioplegia was studied in 23 patients undergoing isolated aortic valve replacement. All had normal coronary arteries. Cardioplegia was induced by infusing 700-1 000 ml of cold Ringers acetate containing 20 mekv K+ selectively into the left coronary artery. Simultaneous blood samples were taken from the radial artery, a central vein and from the coronary sinus before and after cardioplegia. The PO2, O2-saturation and content, PCO2, pH, lactate, glucose, potassium, myoglobin, total creatine kinase (CK), its isoenzyme CK-MB, aspartate aminotransferase (ASAT) and alanine aminotransferase (ALAT) were assessed. Before bypass lactate was extracted by the heart. During the initial 10 to 20 min after cardioplegia there was a marked release of lactate in the coronary sinus. Myoglobin concentration and CK-MB serum activity peaked during the first 4 hours after the release of the aortic cross-clamping. In order to determine the best indicator of myocardial damage after cardioplegia, duration of extracorporeal circulation (ECC-time), aortic occlusion time (AOT), mean myocardial temperature (MMT) and the product of AOT and MMT, referred to as time-temperature area (TTA), were related to possible indicators of myocardial injury, such as enzyme and myoglobin release. The TTA was the best way of expressing the degree of exposure of the heart to ischaemia. The CK-MB to peak area (CK-MB max area) was the best indicator of the degree of ischaemic injury sustained by the heart during operation.

Results Of Aortic Valve Replacement With The Kay-Shiley Disc Valve

Between August, 1966, and April, 1968, aortic valve replacement with the Kay-Shiley disc valve was performed in 60 consecutive patients at the Department of Thoracic Surgery, Karolinska Sjukhuset, Stockholm. The cumulative mortality rate after an observation period ranging from 1 to 3 years was 22%. There were 4 hospital (7%) and 9 late deaths (15%). The causes of death were infection (6), myocardial infarction (4), myo-cardial failure (1), postoperative renal insufficiency (1) and thrombosis around the prosthesis (1).Thrombo-embolic complications were observed in 4 patients (7%), in all related to discontinuation of the anticoagulant therapy. Partial detachment of the prosthesis necessitating re-operation was present in three patients (5%).Forty-two (90%) of the surviving patients were re-examined about a year after surgery, 39 of them being subjected to a follow-up catheterization and 32 also to thoracic aortography with cinetechnique.All patients considered their condition improved after operation. At ...