Simcha Milo

A fatal case of Behcet's disease associated with multiple cardiovascular lesions

Behçets disease is recognised as a chronic multisystem disorder with vasculitis as its underlying pathological process. Cardiac involvement is rare and often associated with poor prognosis. A large right atrial thrombus, pulmonary aneurysms and aortic pseudoaneurysm that developed 17 years after surgery for bilateral renal artery stenosis is presented in a 26-year-old Behçets disease patient. He was admitted to the hospital with fever of unknown origin associated with chest pain, dyspnea, cough, haemoptysis and pulmonary opacity in chest X-ray. Initial pulmonary CT demonstrated small subpleural infiltrates bilaterally, one of which was round and suspected as being metastatic. Examination of open lung biopsy demonstrated haemorrhagic infarct surrounded by some occluded pulmonary arteries. Subsequent CT showed pulmonary aneurysms compatible with Behçets disease. Echocardiography demonstrated a large pedunculated mass in the right atrium. Injection of urographin showed a right atrial mass and a large right pulmonary artery aneurysm. The atrial mass was completely excised during open heart surgery and was identified as being an organising thrombus. Eight weeks later while taking prednisone, he was readmitted because of an infected mid sternal wound. CT showed slight separation of the stemum, retrosternal fluid, pulmonary arteries aneurysm and ascending aorta aneurysm. The next day, the patient died from massive bleeding from his ruptured ascending aortic pseudoaneurysm. Bizarre presentation of arterial and venous thromboses or arterial aneurysm formation, particularly in young patients, should suggest Behçets disease.

A Physical Model Describing the Mechanism for Formation of Gas Microbubbles in Patients with Mitral Mechanical Heart Valves

AbstractThis study was aimed at developing a physical model, supported by experimental observations, to describe the formation and growth of microbubbles seen in patients with mitral mechanical heart valves (MHV). This phenomenon, often referred to as high intensity transient signals (HITS), appears as bright, intense, high-velocity and persistent echoes detected by Doppler ultrasonography at the instant of closure. The long-term clinical implications of HITS has yet to be determined. However, there are reports of a certain degree of neurological disorder in patients with mitral MHV. The numerical analysis has shown the existence of a twofold process (1) nucleation and (2) microbubble growth as a result of cavitation. While mild growth of nuclei is governed by diffusion, explosive growth of microbubbles is controlled by pressure drop on the atrial side of mitral MHV. It was demonstrated that there exist limits on both microbubble size and regurgitant velocity, above which microbubbles grow explosively, and below which growth is almost nonexistent. Therefore, prevention of excessive pressure drops induced by high closing velocities related to the dynamics of closure of mitral MHV may offer design changes in the future generations of mechanical valves.

Long-term follow-up of patients with severe rheumatic tricuspid stenosis

BACKGROUND Tricuspid stenosis is a part of the chronically rheumatic heart. Although rare, when tricuspid stenosis does occur, it occurs in the setting of coexistent mitral and aortic valve disease. The natural course of patients with severe tricuspid stenosis is not well defined. The aim of this study is to present close follow-up of patients with chronic rheumatic heart disease and severe tricuspid stenosis. METHODS AND RESULTS We retrospectively studied 13 patients (11 women and 2 men) with severe tricuspid stenosis who were followed closely for 6 to 31 years. The mean tricuspid pressure gradient ranged from 3 to 9 mm Hg. Twelve patients underwent surgery for mitral and/or aortic valve lesions without complications. Concomitant tricuspid valve surgery was performed on six patients: two De Vega procedures, two Kay plications, and two implantations of Carpentier rings. All these also had leaflet commissurotomy. After surgery, the mean tricuspid gradient decreased in three patients, did not change in two, and increased in one. All 13 patients were treated with diuretics, digoxin, warfarin, and spirinolactone or ACE inhibitors. On their last follow-up visit, every patient had increased jugular venous pressure. Hepatomegaly was found in 6 of 13, leg edema in 4 of 13, and ascites in 1 of 13. CONCLUSIONS Most tricuspid stenos patients are women with severe mitral and aortic valve disease. After successful repair of the mitral or aortic valve, and regardless of the type of tricuspid valve surgery, severe tricuspid stenosis was found to be very well tolerated by all the patients over many years of follow-up.

Umbilical artery flow velocity during maternal cardiopulmonary bypass.

The fetal death rate associated with cardiac operations using cardiopulmonary bypass in pregnant women is as high as 9.5% to 29%. We present a case in which fetal heart rate and umbilical artery flow velocity waveforms were continuously monitored by transvaginal ultrasonography and analyzed in relation to events of the cardiopulmonary bypass. Our findings suggest that hypothermia during cardiopulmonary bypass has potentially deleterious effects on the fetus and should be avoided if possible.

Myocardial protection in operations requiring more than 2 h of aortic cross-clamping

OBJECTIVE Long periods of aortic cross-clamping time during cardiac surgery are associated with high rates of morbidity and mortality because of damage to the myocardium. Recently, we have used a method of myocardial protection based on the principles of hyperkalemic cardioplegic arrest. We use antegrade administration of warm, undiluted blood followed by continuous retrograde infusion of tepid, undiluted blood supplemented with potassium and magnesium. In this study, we have retrospectively reviewed our experience with this method of cardioprotection in operations requiring more than 2 h of cross-clamp time. METHODS We retrospectively reviewed the medical records of 1280 patients who underwent myocardial revascularization, valve repair or replacement, or a combination of both operations between January 1, 1994 and December 31, 1997. Patients were divided into two groups: the short cross-clamp group (SXC) (n = 1144) had cross-clamp times < 120 min (mean, 78 +/- 20 min; range, 35-119 min) and the long cross-clamp group (LXC) (n = 136) had cross-clamp times > 120 min (mean, 154 +/- 31 min; range, 120-277 min). We compared preoperative, operative, and postoperative variables between the two groups. RESULTS Significantly more patients in the long cross-clamp group (43.4%) underwent the combined operation than in the short cross-clamp group (2.3%), and the rate of reoperation was significantly higher in the long cross-clamp group (12%) than in the short cross-clamp group (5%). Despite these differences in operative complexity, we found no difference in hospital mortality rates between the two groups. The only significant postoperative differences were that the long cross-clamp group had a greater need for inotropic agents (43 vs. 29%), higher serum levels of creatine kinase (880 +/- 583 vs. 613 +/- 418) and CK-MB (10.9 +/- 6.4 vs. 5.9 +/- 5.2), and a longer hospital stay (9.6 vs. 6.1 days). CONCLUSION Long, complex operations requiring more than 2 h of cross-clamping can be performed safely with our method of cardioprotection based on continuous retrograde infusion of tepid, hyperkalemic, undiluted blood.

Effect of Preoperative Antibiotic Prophylaxis on Surgical Site Infections Complicating Cardiac Surgery

OBJECTIVE To evaluate the effect of an optimized policy for antibiotic prophylaxis on surgical site infection (SSI) rates in cardiac surgery. DESIGN Prospective cohort study. SETTING Tertiary medical center in Israel. METHODS SSIs were recorded during a 10-year study period and ascertained through routine surveillance using the National Healthcare Safety Network (NHSN) methodology. Multivariable analyses were conducted to determine which significant covariates, including the administration of preoperative prophylaxis, affected these outcomes. RESULTS A total of 2,637 of 3,170 evaluated patients were included, and the overall SSI rate was 8.4%. A greater than 50% reduction in SSI rates was observed in the last 4 years of the study. Overall and site-specific infection rates were similar for patients receiving cefazolin or vancomycin. SSIs developed in 206 (8.1%) of the 2,536 patients who received preoperative prophylaxis (within 2 hours of the first incision) compared with 14 (13.9%) of 101 patients who received antibiotic prophylaxis at a different time (P = .04; odds ratio [OR], 1.8; 95% confidence interval [CI], 1.0-3.3). After accounting for covariates, preoperative hospital stay (5 days or more), an NHSN risk category (2 or 3), age (60 years or more), surgeons role, and the period of measurement were significantly associated with SSIs. Emergency surgery, age, surgeons role, and nonpreoperative prophylaxis were found to be independent predictors of superficial SSI. CONCLUSIONS We observed a progressive and significant decrease in SSI rates after the implementation of an infection control program that included an optimized policy of preoperative prophylaxis in cardiac surgery.

Microbubbles and mitral valve prostheses - transesophageal echocardiographic evaluation.

OBJECTIVE To assess whether microbubbles are associated with a specific type of mitral valve prosthesis and to investigate the relationship of microbubbles to ventricular function and mitral regurgitation. One of the types of spontaneous echocardiographic contrast observed in patients with prosthetic heart valves has been described as microbubbles. METHODS Clinical data and videotapes of patients with a prosthetic mitral valve who had undergone transesophageal echocardiography at the UCLA Medical Center between May 1989 and February 1995 were retrospectively reviewed. There were 109 studies (74 patients) available for review by two independent observers. RESULTS Microbubbles occurred in 49 of the 66 studies of St. Jude valves ( 74%), eight of the 12 studies of Bjork Shiley valves (67%), four of four studies of Medtronic valves (100%) and zero of 23 studies of tissue valves (0%). Patients with an estimated ejection fraction greater than 45% were found to have a much higher likelihood of having microbubbles observed. There was no statistically significant association between the degree of mitral regurgitation and the observation of microbubbles. CONCLUSIONS Microbubbles are a common phenomenon occurring in patients with mechanical mitral prostheses compared with tissue mitral valve prostheses. Their formation depends on the systolic ventricular function, suggesting a cavitation-like phenomenon participating in their formation perhaps due to the rate or velocity of the valve closure.

Ventricular septal rupture complicating myocardial infarction: Comprehensive assessment of cardiac coronary arteries, anatomy, perfusion and function by multidetector computed tomography

38-year-old man was referred for electrocardiogram (ECG)-gated multidetector computed tomography (MDCT) coronary angiography following detection of ventricular septal rupture (VSR) on transthoracic echocardiography 24 h after admission for an acute inferior wall myocardial infarction. He had been treated with primary angioplasty and stenting of a tight distal right coronary stenosis. Detailed, comprehensive evaluation of the VSR, myocardium and coronary arteries was performed with ECG-gated MDCT coronary angiography using a Brilliance 16-slice scanner (Philips Medical Systems, USA). MDCT coronary angiography showed a patent stent and a proximal heterogeneous plaque of borderline significance (Figure 1). The measured global left ventricular function, using the MDCT data, disclosed a mildly reduced ejection fraction of 47%. Regional functional analysis using cine films of the MDCT data depicted regional akinesis of the inferior and inferoseptal mid- and basal segments, manifesting as a marked reduction in myocardial thickening during systole (Video 1 – click here to view). Furthermore, first-pass myocardial perfusion analysis depicted a well-defined, nearly transmural enhancement defect parallel to the akinetic myocardial region (Figure 2). Further detailed analysis of the interventricular septum at end-diastole showed a full-thickness rupture in the mid-inferior septum (Figures 3A and 3B). Of note, the septal rupture occurred at the junction of the normally enhancing anterior septum and the hypoperfused, necrotic, inferior septum and inferior myocardial segments, indicating that this junction line appears to act as a locus minoris resistentiae. The VSR demonstrated near-complete lumen obliteration during peak systole (Figures 3A and 3B), suggesting that at least part of the bordering myocardium (anterior septum) was contracting and, thus, viable. Because the described VSR was small and of no hemodynamic significance, based on imaging findings, it was managed conservatively with follow-up echocardiography. There was no change during a three-month follow-up period.

Right Ventricular Pressure Dynamics After Operation for Pulmonary Stenosis

Right ventricular pressure dynamics were monitored during the first 24 hours after operation for relief of pulmonary stenosis in 9 patients with dysplastic pulmonary valves who underwent total valvectomy. Rather than the expected immediate drop in pressure after total removal of the obstruction, right ventricular pressures required 18 to 24 hours to decrease to physiological values. In 7 patients, the pressures decreased steadily, but in 2, there was an increase in pressure immediately postoperatively, followed by a gradual decrease.

Atrial septal defect associated with a remnant of the valve of the sinus venosus producing unusual drainage of the inferior caval vein

A two-year-old patient had an atrial septal defect associated with a remnant of the valve of the sinus venosus which produced an unusual drainage of the inferior caval vein. The preoperative knowledge of the unusual anatomy allowed the surgeon to repair the anomaly without difficulties.