Simultaneous angiotensin converting enzyme inhibition moderates ventricular dysfunction caused by doxorubicin.

AIMS: The purpose of this study was to determine that the administration of an angiotensin converting enzyme (ACE) inhibitor enalapril would confer protection against doxorubicin-induced experimental heart failure, and attenuate the development of left ventricular dysfunction. METHODS: Seventeen dogs were chronically instrumented with an intracoronary catheter and received doxorubicin weekly for 4 weeks. Animals were assigned to two groups: group 1: untreated heart failure; and group 2: simultaneous enalapril administration (5 mg twice a week). Hemodynamic data were obtained at week 0 and 12. Echocardiography was performed weekly. RESULTS: Survival improved with simultaneous enalapril administration (36% in group 1 vs. 100% in group 2, P=0.04). The increase in the left ventricular end-diastolic pressure was significantly reduced at week 12 (17+/-1 mmHg in group 1 vs. 9+/-1 mmHg in group 2, P=0.0042). The fall in left ventricular stroke work index was significantly prevented (52% in group 1 vs. 21% in group 2, P=0.006). The increase in right ventricular end-diastolic diameter was significantly reduced by enalapril prophylaxis. CONCLUSION: Simultaneous treatment with enalapril was beneficial in the prevention of doxorubicin-induced cardiomyopathy.

Telemetrically monitored arrhythmogenic effects of doxorubicin in a dog model of heart failure.

A model of chronic heart failure has been induced in dogs by repeated intracoronary infusion of doxorubicin, which is an antineoplastic medication that has dose-limiting cardiotoxic side effects. Although many of the dogs receiving doxorubicin develop typical signs of dilated cardiomypathy over 4-6 weeks, some of them suddenly die before completing the four weekly infusions of the drug. The present study was undertaken to determine whether such sudden death may be caused by the development of fatal arrhythmias during doxorubicin treatment. This was assessed by telemetrically monitoring the EKG of seven dogs, which received intracoronary infusion of 1 mg/kg doxorubicin given in four divided weekly doses. The recordings were obtained for 8-10 h on alternate days up to 4 weeks. Echo-cardiographic recordings were obtained once a week. The acute effects with each infusion of doxorubicin included a significant increase in heart rate, and no significant change in QRS complex. The cumulative prolonged effects of doxorubicin included slight reduction in QRS amplitude and duration, and marked arrhythmic changes. Four out of seven dogs showed a spectrum of arrhythmic events such as single or groups of premature ventricular complexes (PVCs), bigeminy, ventricular tachycardia (VTAC), ventricular fibrillations (VFIB), and asystole. All dogs did not show each of the events listed above and the same dog did not show all the events all the time. One of these four dogs developed VFIB for 25 min and then asystole leading to sudden death. These studies conclusively showed that fatal arrhythmias develop in some of the dogs receiving doxorubicin treatment accounting for the sporadic incidence of sudden death. Prophylactic treatment with antiarrhythmic agents may prevent such adverse events.

Primary thoracoscopic evaluation of pleural effusion with local anesthesia: an alternative approach.

OBJECTIVE: The development of a thoracoscopically assisted technique to be performed with the patient under local anesthesia for both diagnostic and therapeutic purposes when treating pleural effusions and empyemas in high-risk surgical patients. METHODS: Twenty patients with pleural effusion or empyema who were also determined to be at high risk for complications following a thoracotomy, pleural biopsy, general anesthesia, or all of these, underwent placement of a thoracoscope while under local anesthesia followed by thoracic fluid drainage, pleural biopsy, and pleurodesis as required. Patients were retrospectively evaluated for a variety of factors including personal history, pre-existing medical conditions, and pre- and postoperative course. RESULTS: The average age of the patients was 59 years (18 to 89) with a 55% male/45% female sex distribution. Patients had this procedure as a consequence of malignancy (50%), empyema (30%), spontaneous pneumothorax (10%), bronchiectasis (50%), or heart failure (5%). The average duration of the procedure was 62 minutes (20 to 190), with an average of 861 mL of fluid drainage, and 114 mL of estimated blood loss. The tube thoracostomy was usually removed on the sixth (0 to 13) postprocedure day. This procedure was well tolerated by the patients with the majority of pain management being achieved with patient controlled analgesia (58%). The direct complication rate was 10%, with 2 patients requiring endotracheal intubation. CONCLUSION: This novel thoracoscopic procedure represents an acceptable alternative to the traditional treatment of pleural effusions and empyema with comparable outcome parameters and morbidity. This technique may eventually become the standard of care for the treatment of pleural effusions.

Expedient pulmonary embolectomy for acute pulmonary embolism: improved outcomes.

Indications regarding surgical pulmonary embolectomy for treatment of submassive/massive acute pulmonary embolism remain controversial. An institutional experience with pulmonary embolectomy for acute pulmonary embolism (APE) was reviewed. A retrospective analysis of all patients undergoing pulmonary embolectomy for APE from September 2004 to January 2007 was conducted. Demographic data, clinical presentation and outcomes were analyzed. Fifteen patients underwent surgery for APE over a period of 27 months [average age 59.6 (range 35-89) years, (seven male, eight female)]. Six (40%) patients were admitted with known APE and nine patients exhibited post admission APE (seven - after surgical procedures, two - after cerebrovascular accident). Clinical presentation included dyspnea (86.67%), hemodynamic instability requiring continuous vasopressor support (40%), echocardiographic evidence of right ventricular dilatation (80%). Ten patients undergoing early/expedient embolectomy all survived while delayed surgery in the other five patients (>24 h) was associated with 60% mortality. Expanding indications for early surgical pulmonary embolectomy has stemmed from reliable echocardiographic identification of right ventricular compromise and recognition of these findings as harbingers of subsequent hemodynamic embarrassment. Our series underscores the benefit of early consideration and performance of pulmonary embolectomy in these critically ill patients.

Circadian rhythm has no effect on mortality in coronary artery bypass surgery.

BACKGROUND: The circadian variation that affects atherosclerosis has not been studied in the surgical patient. The circadian variation in mortality dependent on the time of surgery was examined in patients undergoing coronary artery bypass graft (CABG) surgery. METHODS: A 4-year retrospective review of all CABG patients (n = 3140) from 1999 to 2002 was undertaken. The patients were divided into elective, urgent, and emergency cases. The cases were subdivided according to the start time of the operation as morning (7 AM to 2 PM = AM), afternoon (2 PM to 8 PM = AF), and night (8 PM to 7 AM = NT). The outcome was mortality within 30 days and compared for three different time frames: (1) AM versus AF (2) AM versus NT (3) AF versus NT for each prioritized group. Risk factors and number of anastamoses were compared for each group. Sigma Statistical package and Z-test for two group comparison were used for analysis. t-Test was used to compare age and ejection fraction. RESULTS: No statistically significant difference in mortality was observed for the elective and urgent groups for each of the time periods compared. The emergency cases had significantly increased deaths in the AM and NT compared to the AF (p < 0.01 and p < 0.05, respectively). There was no statistically significant difference with respect to age, gender, number of anastamoses performed, ejection fraction, and preoperative risk factors between groups. CONCLUSIONS: The mortality for nonemergent CABG is independent of the timing of surgery. Circadian variation does not influence the outcome in cardiac surgical patients.

Cardiac valve papillary fibroelastoma: surgical excision for revealed or potential embolization.

Cardiac papillary fibroelastomas (CPF) are benign endocardial papillomas commonly formed from valve endothelium. The majority of tumors are found on the left side of the heart, with only a few case reports of pulmonary valve fibroelastomas. We report here a case of pulmonary valve papillary fibroelastoma that was successfully managed with simple excision of the mass.

Telemetric recording of intrapleural pressure.

BACKGROUND: Monitoring of intrapleural pressure (IPP) is used for evaluation of lung function in a number of pathophysiological conditions. We describe a telemetric method of non-invasive monitoring of the IPP in conscious animals intermittently or continuously for a prolonged period of time. MATERIALS AND METHODS: After IACUC approval, six mongrel dogs were used for the study. After sedation, each dog was intubated and anesthetized using 0.5% Isoflurane. A telemetric implant model TL11M2-D70-PCT from Data Science International was secured subcutaneously. The pressure sensor tip of the catheter from the implant was inserted into the pleural space, and the catheter was secured with sutures. The IPP signals were recorded at a sampling rate of 100 points/second for 30 to 60 min daily for 4 days. From these recordings, the total mean negative IPP (mmHg), and the total mean negative IPP for a standard time of 30 min were calculated. In addition, the actual inspiratory and expiratory pressures were also measured from stable recording of the IPP waveforms. RESULTS: In six dogs, the total mean +/- SD negative IPP was -10.8 +/- 10.6 mmHg. After normalizing with respect to acquisition time it was -13.2 +/- 11.2 mmHg/min. The actual inspiratory pressure was -19.7 +/- 15.3, and the expiratory pressure was -11.0 +/- 12.9. CONCLUSIONS: Our study demonstrates that telemetric monitoring of IPP can be performed reliably and non-invasively in conscious experimental animals. The values for IPP in our study are compatible with the results of other investigators who used different methods of IPP measurement. Further work may show this method to be helpful in understanding the pathophysiology of various breathing disorders.

Pseudoaneurysms of the ascending aorta following coronary artery bypass surgery.

BACKGROUND: Ascending aortic pseudoaneurysms following prior cardiac procedures are a rare entity. We reviewed our institutional experience given the isolated case reports in the literature. METHODS: A 10-year retrospective review identified 5 patients who underwent ascending aorta pseudoaneurysm repair. There were 3 women and 2 men with a median age of 70 years (range 63 to 79 years). Median duration from initial CABG to pseudoaneurysm repair was 5 years (range 5 months to 18 years). The clinical presentations included dyspnoea (2 patients), chest pain, fever of unknown origin, and a pulsatile mass. Four patients underwent urgent investigation and surgery. Diagnosis was established via CT scan (3 patients), transesophageal echocardiogram (1 patient), and MRA (1 patient). Two patients had a prior history of sternal wound infection. RESULTS: Mortality was 60%. One survivor experienced a stroke. The etiology was prior cannulation site in 4 cases and vein graft anastamotic site in 1. Necrotic aortic tissue was noticed in 2 cases. Aortic tissue cultures were negative in all the patients. Cardiopulmonary bypass was established prior to sternotomy in 4 cases and 1 case was performed off-pump. Inadvertent rupture of the pseudoaneurysm (without exsanguination) occurred in 2 cases following sternotomy. Repair was performed with bovine pericardial patch in 2 cases and plication in 3 cases. CONCLUSION: This highlights the varied presentation, necessity for urgent diagnosis and repair with a high operative mortality due to the late presentation. Aggressive diagnosis should be sought and consideration should be given to catheter-based interventions for initial treatment.

Correlation of blood volume values and pulmonary artery catheter measurements.

OBJECTIVE: To correlate the values generated by direct total blood volume measurement with pulmonary artery catheter parameters and commonly used laboratory values in the management of critically ill patients. METHODS: This study was carried out at the Lutheran Medical Center, Brooklyn, New York, United States of America, during the period 1998-1999. We prospectively correlated the total blood volume (TBV) values generated by the blood volume analyzer (BVA)-100 using I131-tagged albumin, with the values obtained from pulmonary artery catheter (PAC) of central venous pressure, pulmonary capillary wedge pressure, cardiac output, and with laboratory values of hematocrit, lactate, arterial blood gas and mixed venous blood, in critically ill patients. Twenty-four intensive care unit (ICU) patients were studied. INCLUSION CRITERIA: Admission to the intensive care, pulmonary artery catheter insertion and (APACHE) II Acute Physiology and Chronic Health Evaluation score of 8-30 (mean=17.875). EXCLUSION CRITERIA: Pediatric patients, hemodynamically normal or stable patients, pregnancy, and critically ill patients that were managed in an ICU setting without PAC catheter. Height and weight were recorded. After the collection of an initial blood sample (5 cc), one cc of I131-tagged albumin (15-25 microcuries) was injected using a patented syringe. Five venous samples were collected after the isotope injection. RESULTS: The collection times were entered into the BVA-100. Hematocrit measurements were performed in duplicate. Blood samples were centrifuged and one ml from the plasma of each sample was pipetted (in duplicate) into the sample tube then placed into the BVA-100. The results showed that the TBV did not correlate with either pulmonary capillary wedge pressure or central venous pressure, and except for the cardiac output, there is no correlation between pulmonary capillary wedge pressure readings or TBV results and the other parameters considered in this study. CONCLUSION: This method can be released from the research fields and can be safely incorporated into the clinical arena. It provides an accurate assessment of the volume status in intensive care unit patients.

Open heart surgery in patients 85 years and older.

BACKGROUND: There has been an increase in the number of elderly patients considered for cardiac surgery. Several reports have documented acceptable morbidity and mortality in patients 80 years and older. The results from surgical patients 85 years and older were analyzed. METHODS: The records of 89 consecutive patients 85 years and older having cardiac operations between June 1993 and May 1999 were retrospectively reviewed. For purposes of statistical analysis follow-up was considered as a minimum of one office visit to the surgeon, cardiologist, or internist at least 1 month postoperatively. RESULTS: Eighty-seven patients underwent coronary artery grafting and two patients had mitral valve replacement. Follow-up was 100% complete. The operative mortality rate was 12.3%; probability of in-hospital death was 8.2%; risk-adjusted mortality rate was 3.2%. The complication rate was 31.5%. The actuarial 1-, 3-, and 5-year survivals were as follows: 75%, 67%, and 40%. Multivariate predictors of 30-day mortality were preoperative EF, less than 30% (p = 0.029) and postoperative renal failure (p = 0.0039). CONCLUSIONS: Cardiac surgery can be performed in patients 85 years and older with good results. There is an associated prolonged hospital stay for elderly patients. Consistent successful outcomes can be expected in this patient population with selective criteria identifying risk factors.

Cardiac surgical procedures and glove reinforcements.

The purpose of this prospective study is to determine the frequency and site of glove perforation during cardiac surgical procedures. Over a period of six months, gloves from 206 surgical team members were collected at the conclusion of surgery. All cases of known perforations were eliminated from the study. The percentage of glove perforation was 14%. The distribution of perforation across locations of the hand was significantly unequal (P = 0.001). We found that 73% of the punctures occurred in one of four contiguous locations on the glove: the radial side of the index finger (28%), the radial side of the thumb (21%), the palmar side of the index (14%), and the palmar side of the thumb (10%). Therefore, we recommend glove reinforcement on these locations that would provide better protection against transmission of infectious agents. Discomfort from restricted dexterity and impaired sense of touch with double gloving renders glove reinforcement a suitable alternative for universal precautions, especially in cardiac surgery while high level of perfection and dexterity were needed in lengthy, critical operations.