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Biomedical subjects

S T Raza

Publications and source records attributed to S T Raza.

14 recordsLinked to original sources
PubMed1998

Effect of implantable cardioverter-defibrillator implantation on surgical morbidity in the CABG Patch Trial. Surgical Investigators of the Coronary Artery Bypass Graft Patch Trial.

BACKGROUND: The Coronary Artery Bypass Graft (CABG) Patch Trial tested the hypothesis that prophylactic insertion of an implantable cardioverter-defibrillator (ICD) improves survival rates after high-risk CABG. We compared group-specific perioperative morbidity and mortality rates. METHODS AND RESULTS: Patients were randomized intraoperatively to undergo CABG (control subjects, n = 454) or CABG plus ICD implantation (n = 446). There were no significant differences between groups in the incidence of diabetes, ejection fraction < 0.25, end-diastolic pressure, prior myocardial infarction, or congestive heart failure. Cardiopulmonary bypass time averaged 106 minutes in control subjects and 127 minutes in the ICD group. At the inception of the trial, investigators were concerned that ICD therapy could increase surgical mortality rates or the incidence of shock, bleeding, congestive heart failure, arrhythmias, or deep sternal wound infection. Of these, only sternal wound infection was significantly more frequent in the ICD group (2.2% versus 0.4%, P < 0.05). Also more common in the ICD group were infection at a wound or catheter site (12% versus 6%), urinary tract infection (4% versus 1%), pneumonitis (8% versus 4%), respiratory insufficiency (13% versus 8%), transient central nervous system deficit (6% versus 2%), and psychotic reaction (4% versus 1%). The all-cause death rate was 6.7% in the ICD group and 4.6% for control patients (P = NS) at the time of the last surgical death, postoperative day 48. CONCLUSIONS: Epicardial ICD insertion during CABG is associated with an increase in perioperative infection. Although reporting bias may have influenced the data, if ICD insertion is indicated in CABG patients, metachronous endocardial implantation should be considered.

Adult↗
PubMed1996

Comparison of long-term patency of "horseshoe" saphenous vein grafts with and without valves.

OBJECTIVE: The paper analyzes the long-term patency of valveless and valvular limbs of reversed saphenous veins. METHODS: Between 1983 and 1988, 335 patients underwent isolated coronary artery bypass grafting (CABG) with 1,329 grafts. Eighty-three patients had follow-up angiography over 8-12 years. The side-to-side saphenous vein to aortic "horseshoe" anastomosis was created just before the first valve from the ankle (naturally a valveless portion). The valveless (ankle end) was depicted in every case. These patients with angiography were similar to 252 patients without angiography in terms of age, gender, number of grafts, diseases vessels, single (A) and sequential (B) grafts and actuarial survival. In the 83 patients, graft patency was 75%. Overall patency was the same in B versus A grafts (76% versus 74.6%); valveless patency (78.7%) was slightly better than valvular patency (73.3%). RESULTS: In patients with B grafts (88.6%) valveless patency was significantly better than valvular patency (71.9%) (P < 0.02). The patency of B-valveless to the left coronary bed was also better, (86.8% versus B-valvular 70.5%, P < 0.04). Attrition of the B-valveless and B-valvular grafts was similar up to 8 years, but by the 12th year it had become significantly different (P < 0.05). The 12-year actuarial survival rate of the patients was 87.7%. CONCLUSIONS: We recommended the use of valveless vein segments when possible.

Actuarial Analysis↗
PubMed1990

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.

Adult↗
PubMed1989

Sequentially paced heterotopic heart transplant in the left chest provides improved circulatory support for the failed left ventricle. A potential biologic bridge to orthotopic transplantation.

Acute experimental transplantation of an allograft heart in a heterotopic position was performed in 14 sheep. The donor heart was implanted in the left side of the chest with left atrial, aortic, and pulmonary artery anastomoses. Hemodynamic studies were performed to evaluate the physiologic effects of the procedure, particularly when recipient left ventricular failure was produced by inflow and outflow obstruction. Pacing techniques were developed and tested to coordinate the rhythm of the two hearts either synchronously or sequentially with variable intervals between depolarization of the two hearts. Hemodynamic studies were performed to evaluate the rhythm that would most optimize the physiology. The cardiac index remained essentially unchanged when the dominant circulatory support was shifted from recipient left ventricle to donor left ventricle by producing recipient left ventricular failure (3.79 +/- 0.6 to 3.30 +/- 0.8, p = no significant difference). Consistent and reliable paced rhythms were achieved in each case. The cardiac index was significantly higher when the hearts were paced sequentially rather than synchronously (3.76 +/- 0.5 versus 3.29 +/- 0.5, p less than 0.04). Allograft donor hearts small in size or slightly inadequate otherwise, which may be unsuitable for orthotopic heart transplantation, may still be used heterotopically for short-term support. Their use would maximize the use of all donor organs and the survival of patients awaiting a suitable organ. Further, it may also be possible to use sequentially paced xenografts heterotopically for short-term left ventricular assistance as a bridge to orthotopic heart transplantation.

Animals↗
PubMed1988

Effects of antegrade cardioplegic infusion with simultaneously controlled coronary sinus occlusion on preservation of regionally ischemic myocardium after acute coronary artery occlusion and reperfusion.

This study was conducted to assess the protective effects of antegrade infusion of cardioplegic solution with simultaneously controlled coronary sinus occlusion on regionally ischemic myocardium after acute coronary occlusion and reperfusion. Twelve sheep were subjected to 1 hour of occlusion of the distal left anterior descending coronary artery. Sheep in group I (n = 6) were subjected only to infusion of potassium crystalloid cardioplegic solution into the aortic root, whereas in group II (n = 6) a stitch was snared around the proximal coronary sinus for its subsequent occlusion during antegrade infusions of cardioplegic solution. All animals were placed on cardiopulmonary bypass. Five hundred milliliters of cardioplegic solution at 4 degrees to 8 degrees C was administered in three divided doses during the total cross-clamp period of 30 minutes. The occlusion of the left anterior descending artery was then released, and the animals were weaned from bypass and studied for an additional 4 hours. Coronary sinus pressure, myocardial temperature, regional function assessed by pairs of ultrasonic crystals, global function assessed by rate of rise of left ventricular pressure and cardiac output, and the area at risk and area of necrosis were determined. The heart was excised at the end of the experiment and stained. Animals treated by the technique of antegrade infusion combined with coronary sinus occlusion had more homogeneous myocardial cooling during cardioplegic infusions and better recovery of the first derivative of left ventricular pressure and regional segment shortening at 90 and 270 minutes of reperfusion than those treated with antegrade infusion alone (p less than 0.01 and p less than 0.05, respectively). The group treated by antegrade infusion of cardioplegic solution combined with coronary sinus occlusion had an area of necrosis/area at risk ratio of 40.5% +/- 1.2%; the antegrade infusion group, 58.3% +/- 4.1% (p less than 0.01). These data suggest that antegrade infusion combined with coronary sinus occlusion may be an improved method of global and regional myocardial protection in the presence of an occluded coronary artery.

Animals↗
PubMed1985

Clinical advantages of papaverine cardioplegia.

To determine the efficacy of papaverine in improving myocardial protection by causing a uniform distribution of the cardioplegic solution, a prospective study was carried out in 200 consecutive patients undergoing various open heart procedures. Several parameters (creatine kinase MB, electron microscopy of myocardium, perioperative myocardial infarction rate, frequency of postoperative arrhythmias) were monitored and compared with those of a control group which consisted of the previous 200 consecutive patients in whom the same cardioplegic solution was used, but without papaverine. In the papaverine group the operative mortality due to low cardiac output was 0.5% compared to 3%, and the spontaneous recovery of the heart after release of the aortic cross-clamp was 89% compared to 47% in the control group (P less than 0.01). The perioperative myocardial infarction rate was 5% and the incidence of postoperative temporary arrhythmias was also 5% in the papaverine group, while in the control group the perioperative myocardial infarction rate was 10% and the postoperative arrhythmia incidence was 13% (P less than 0.01).

Adolescent↗
PubMed1984

Influence of length of aortic occlusion with cold potassium cardioplegia on early and late mortality in cardiac valve replacement.

This study determines if prolonged aortic crossclamp time (ACC) with the use of cold potassium cardioplegia during elective cardiac valve replacement contributed to the risk of operative mortality in 225 patients. In Group I (143 patients), the ACC was less than 120 minutes (mean 86) and in Group II (82 patients), it was greater than 120 minutes (mean 146). The preoperative variables showed that Group II contained more severely ill patients who were undergoing more complex operations than in Group I. The operative mortality rate was 7% in Group I and 10% in Group II (p = not significant). Postoperative inotropic support was required in 13% of Group I and 30% of Group II patients (p less than 0.005). Operative mortality in patients in New York Heart Association (NYHA) functional class I and II was 0 and in patients in classes III and IV it was 13% (p less than 0.00008). Five percent of patients in NYHA classes I and II and 32% in classes III and IV required inotropic support (p less than 0.000005). The actuarial survival at 60 months was 88 +/- 3% for Group I and 77 +/- 7% for Group II (NS). For the NYHA class I and II patients, however, it was significantly better (98 +/- 2%) than class III and IV patients (75 +/- 5%) (p less than 0.0001). Analysis by logistic equation revealed that the NYHA functional classes III and IV were significant incremental risk factors for probability of in-hospital mortality (p less than 0.0001) but not the ACC time (p greater than 0.1).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1984

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.

Adult↗
PubMed1979

Dacron patch enlargement of anterior wall of left ventricle after aneurysmectomy with concomitant infarctectomy.

The basis for left ventricular aneurysmectomy with cardiopulmonary bypass was established 20 years ago. There is a higher risk in patients who undergo operation within 2 months of myocardial infarction. In these patients there may be no clear demarcation between devitalized tissue and residual healthy myocardium. A case is reported in which anterolateral aneurysmectomy with concomitant infarctectomy so compromised left ventricular size that the anterolateral wall of the left ventricle had to be reconstructed with a Dacron patch graft.

Adult↗
PubMed1977

Early and long-term effects on direct myocardial revascularization on cardiac function: a prospective study using multivariable physiological analysis.

Perioperative and late follow-up hemodynamic cardiovascular studies to assess the effects of direct myocardial revascularization on cardiac function objectively have been completed on 51 patients. Analysis of the data delineated three distinct groups basedon the patterns of their early postoperative recovery. Group I patients (12) had a hyperdynamic cardiovascular response to operation and returned to a normal physiological range of cardiac function within 24 hours. Group II patients (24) initially had moderate to severe myocardial decompensation postoperatively but responded to inotropic support and moved into the normal physiological range within 24 to 48 hours. Group III patients (15) had severe, prolonged myocardial decompensation with little response to inotropic support. There were no early deaths in Group I, 1 early iatrogenic death in Group II, and 2 deaths from sepsis, 1 in Group I and 1 in Group II. All 7 cardiogenic deaths occurred in Group III patients. Late follow-up studies 4 to 23 months postoperatively have been completed on 29 patients. These showed cardiovascular stability in the mean values in Groups I and II. Significant improvement in mean cardiac function was seen in surviving Group III patients.

Adult↗
PubMedDate not supplied

Limited access left thoracotomy for reoperative coronary artery disease: on or off pump.

Between 1971 and 1988 left thoracotomy was performed on pump for selected reoperations. Since 1993, 92 patients were operated on with a limited approach and an increased number of cases were done off pump (70 patients). The purpose of this paper is to describe the transition of our operative techniques from on pump to off pump for reoperative coronary patients. From 1995 to 1999, 22 patients (Group 1) were operated on pump and 70 patients (Group II) off pump; 86 of 92 (93.5%) had reoperations. The demographic data were similar in these two groups regarding age, gender, ejection fraction, and total number of grafts performed. In this study 92 patients had a crude mortality of 4.3%. Limited access thoracotomy provides safer reoperation than previously (1971-1988) with an improved on or off pump (4.5% vs. 4.3%) mortality, compared to the on pump mortality of 10% between 1971-1988. Off-pump operations are performed with increasing frequency and with the same risk and less postoperative complications.

Aged↗