Biomedical subjects
O P Yadava
Publications and source records attributed to O P Yadava.
Myocardial revascularisation after acute myocardial infarction.
One hundred and twenty-three patients had coronary artery bypass grafting (CABG) within 30 days of acute myocardial infarction (AMI) from May 1992 to November 1997. Commonest infarct was anterior transmural (61.8%) and commonest indication of surgery was post-infarct persistent or recurrent angina (69.1%). Ten patients were operated within 48 h and 36 between 48 h to 2 weeks of having MI. Out of these, nine patients were having infarct extension and cardiogenic shock at the time of surgery. Pre-operatively fourteen patients were on inotropes of which six also had intra-aortic balloon pump (IABP) support. All patients had complete revascularisation with 3.8+/-1.2 distal anastomoses per patient. By multivariate analysis, we found that independent predictors of post-operative morbidity [inotropes >48 h, use of IABP, ventilation >24 h, ICU stay >5 days] and complications [re-exploration, arrhythmias, pulmonary complications, wound infection, cerebrovascular accident (CVA)] were left ventricular ejection fraction (LVEF) <30%, Q-wave MI, surgery <48 h after AMI, presence of pre-operative cardiogenic shock and age >60 years (P < or = 0.01). Mortality at 30 days was 3.3%. LVEF <30%, Q-wave MI, surgery <48 h after AMI, presence of pre-operative cardiogenic shock and age >60 years were found to be independent predictors of 30 days mortality (P < or = 0.01). Ninety patients were followed up for a mean duration of 33 months (1 to 65 months). There were three late deaths and five patients developed recurrence of angina. To conclude, CABG can be carried out with low risk following AMI in stable patients for post-infarct angina. Patients who undergo urgent or emergent surgery and who have pre-operative cardiogenic shock, IABP, poor left ventricular functions, age >60 years and Q-wave MI are at increased risk.
Mechanism of stroke complicating cardiopulmonary bypass surgery.
BACKGROUND: Stroke is a devastating complication of cardiopulmonary bypass (CPB) surgery which occurs in 1 to 5% of cases. Strategies to reduce its incidence require a knowledge of the underlying pathology and aetiology. AIMS: To determine the incidence, pathology and aetiology of stroke complicating CPB. METHODS: Prospective review of clinical, operative and cranial CT scan findings in all cases of stroke complicating CPB procedures in our institution over an 18 month period. RESULTS: Twenty-one (1.6%, 95% CI 0.9-2.3%) cases of stroke were identified from 1336 CPB procedures. Cranial CT scan, performed in all but one patient, was normal in three patients or consistent with ischaemic stroke in 17 patients. There were no cases of haemorrhagic infarction or intracerebral haemorrhage. It was difficult to differentiate embolic and borderzone infarcts in two cases. After considering the clinical, operative and CT scan features together, 12 (57%, 95% CI 36-78%) of the cases were felt to be embolic in origin and nine (43%, 95% CI 22-64%) due to hypoperfusion in a borderzone. CONCLUSIONS: This study demonstrates that stroke remains an important complication of CPB procedures with an incidence in our series of 1.6%. The pathologic type of stroke is predominantly ischaemic in nature due to either cerebral embolism or borderzone infarction. Strategies for stroke prevention in patients undergoing CPB should be targeted primarily at these two mechanisms.
Plasma platelet activating factor degradation and serum lipids after coronary bypass surgery.
OBJECTIVE: Platelet activating factor (PAF) is a potent mediator in inflammatory responses and maybe involved in various disease states. Degradation of PAF in plasma results from the action of a specific, lipoprotein associated, acetylhydrolase. The aim was to determine plasma acetylhydrolase activity under optimised conditions, PAF half life, phospholipase A2 activity, the lyso-derivative of PAF (lyso-PAF), and lipids in patients undergoing coronary artery bypass grafting. METHODS: The study variables were determined 3 d and 7 d following coronary artery surgery and compared to presurgical values in 15 males, age 55(SEM 4) years. RESULTS: Three days following coronary bypass grafting, total, LDL and HDL cholesterol fell significantly by 30%, 45%, and 15% respectively (p less than 0.001), all decreases correlating with bypass time (p less than 0.025). Concentrations remained low at 7 d (p less than 0.005). Acetylhydrolase activity fell by 38% (p less than 0.001) at 3 d post-surgery and remained depressed, but plasma PAF half life did not change after surgery. The inverse relationship between acetylhydrolase activity and plasma PAF half life preoperatively (p less than 0.01) was not evident after surgery. There was a direct linear relationship between acetylhydrolase activity and both total (p less than 0.002) and LDL cholesterol (p less than 0.001) before surgery. The fall in acetylhydrolase activity correlated with the fall in these lipids (p less than 0.01) but not with that of HDL cholesterol. Plasma lyso-PAF decreased by 65% (p less than 0.001) at 3 d and remained depressed (p less than 0.001). Plasma phospholipase A2 activity increased by 60% (p less than 0.01) and remained raised (p less than 0.05), the increase at 3 d being related to bypass time (p less than 0.05). CONCLUSIONS: The large fall in plasma acetylhydrolase activity after coronary bypass grafting is consistent with the fall in plasma lipids. However, the absence of a significant change in the measured PAF half life in plasma raises questions as to the pathophysiological significance of the decrease in acetylhydrolase activity.
Esophageal malignancies: is preoperative radiotherapy the way to go?
During the period 1969 to 1988, 68 patients with esophageal malignancy were subjected to preoperative radiotherapy consisting of 30 Gy over 3 weeks followed by esophagectomy after a wait of 2 weeks. Sixty-two of 68 patients (91%) were followed up retrospectively (5-year survival rate, 17.2%; 10-year survival rate, 4.8%). Radiosensitivity of the tumor was graded by a radiation effect scoring method devised by us, and this was found to correlate with long-term prognosis (p = 0.05). Radiotherapy "sterilized" malignant involvement of adventitia and draining lymph nodes in 8 patients and thereby converted "palliative" into potentially "curative" resections with a mean survival of 57.2 months in this group of patients. Preoperative radiotherapy was found to increase the survival, decrease the incidence of residual tumor at the resected stump, reduce the incidence of local recurrence, and increase the resectability rate.
Structural study of the quinone pigments from the roots of Cassia alata.
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Unruptured sinus of valsalva aneurysm presenting as acute coronary syndrome.
An unusual presentation of sinus of Valsalva aneurysm causing right ventricular outflow tract obstruction and presenting as acute coronary syndrome is reported. A 38-year-old lady presented with ischemic chest pain, probably due to embolization from an unruptured sinus of Valsalva aneurysm.
Lesser invasive coronary artery bypass surgery: a critical reappraisal.
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