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Scientific Articles


A comparison of esmolol and diltiazem for heart rate control during coronary revascularisation on beating heart.

Chauhan S, Saxena N, Rao BH, Singh RS, Bhan A.

Department of Cardiac anaesthesia and Cardiac Surgery Cardiothoracic Centre, All India Institute of Medical Sciences, New Delhi, India. sancha@medinst.ernet.in.

This prospective study compared control of heart rate and haemodynamics during coronary artery revascularization without cardiopulmonary bypass using either esmolol or diltiazem. Sixty adult patients with one or two vessel coronary artery disease, were randomly divided into 2 groups. Group A (n=30) received a 50 microg/kg/ loading dose of esmolol followed by a 100 microg/kg/hr infusion, for control of heart rate during surgical anastomosis of the coronary vessel. Group-B (n=30) received 0.15 mg/kg of diltiazem as a loading dose followed by a 5 mg/hr infusion for heart rate control, during the anastomosis. It was seen that heart rate control was better in group A, 51.4 +/- 1.3 beats/min, (p <0.01) than in group B, 69.6 +/- 3.0 beats/min (p <0.05), as compared to baseline values of 80.6 +/- 12.1 beats/min in group A and 82.4 +/- 10.6 beats/min in group B respectively. Systemic vascular resistance and pulmonary artery wedge pressure were unchanged in group A but mean pulmonary artery pressure and pulmonary vascular resistance were significantly raised. Group B patients had decreased systemic vascular resistance, mean pulmonary artery pressure and pulmonary artery wedge pressure, and reduced right ventricular stroke work index at the time of distal coronary anastomosis. We concluded that although esmolol provided dramatically slower heart rates, during surgery, the resulting elevations in mean pulmonary artery pressure and pulmonary vascular resistance would require caution if used in patients with underlying right ventricular dysfunction from ischaemia or infarction. Diltiazem by virtue of its effects on systemic vascular resistance, cardiac output, and lowering of mean arterial pressure may be a better choice in hypertensive patients.

Life-threatening esophageal injury after transesophageal echocardiography.

Rawat RS, Saxena P, Panigrahi B, Bhan A.

Heart Lung Circ. 2007 Oct;16(5):382-4. Epub 2007 Mar 6.

Pretreatment of human myocardium with adenosine.

Wasir H, Bhan A, Choudhary SK, Sharma R, Chauhan S, Venugopal P.

Department of Cardiothoracic and Vascular Surgery, Cardiothoracic Sciences Centre, All India Institute of Medical Sciences, Ansari Nagar, 110 029, New Delhi, India.

OBJECTIVES: While the role of adenosine pretreatment in animals has been well established, the role in humans has been controversial. We performed this prospective, randomized study to find out the usefulness of adenosine pretreatment in humans. PATIENTS AND METHODS: Twenty patients undergoing coronary artery bypass surgery for severe triple vessel disease and left ventricular dysfunction (ejection fraction<35%) formed the study population. The adenosine group (n=10) received adenosine infusion (200 microg/kg) before aortic cross-clamp. The control group (n=10) received only normal saline injection. Cardiac function indices were assessed post-operatively. RESULTS: In the adenosine group there was a significant increase in cardiac output in the post-operative period from 3.46+/-1.06 to 4.46+/-0.92 l/min (P<<0.05). The cardiac index increased significantly in the adenosine group from 1.97+/-0.43 to 2.54+/-0.5 l/min per m2 (P<<0.05) and even when compared with the control group this increase was significant (adenosine group vs. control group, P=0.03). Systemic vascular resistance fell from 1898.8+/-558.4 to 1134.9+/-530.7 dyne/s per cm(-5) (P<<0.05) in the adenosine group. The pulmonary artery wedge pressure fell significantly in the adenosine group from 11.1+/-5.0 to 7.2+/-2.6 mmHg (P<<0.05). Patients in the adenosine group maintained a lesser increase in resting heart rate post-operatively (96.1+/-13.4 to 114.1+/-18.7 beats/min) (P=0.7), as compared to the control group where the increase in the heart rate was significant (77.1+/-8.3 to 109.7+/-14.9 beats/min) (P<<0.05). In the adenosine group only one patient (10%) had a raised creatine phosphokinase (MB) level at 12 h post-operatively as compared to three patients (30%) in the control group (P<0.05). CONCLUSIONS: Adenosine pretreatment appears to protect against reperfusion injury in human hearts and thus results in improved post-operative haemodynamics.

Ann Thorac Surg. 2000 May;69(5):1643-4.

Harmonic scalpel: a word of caution.

Talwar S, Bhan A, Sharma R, Venugopal P.

Ann Thorac Surg. 2000 Apr;69(4):1216-21.

Surgical myocardial revascularization without cardiopulmonary bypass.

Bhan A, Choudhary SK, Mathur A, Sharma R, Sahoo M, Agrawal R, Venugopal P.

Cardiothoracic Centre, All India Institute of Medical Sciences, New Delhi. shivmeet@medinst.ernet.in

BACKGROUND: Though coronary artery bypass grafting (CABG) without cardiopulmonary bypass is being performed with increasing frequency, in the absence of adequate angiographic follow-up, safety, reproducibility, and efficacy of the procedure remain doubtful. In this prospective study, we report the results obtained by 100% angiographic follow-up of 96 consecutive patients. METHODS: A total of 96 patients (age range 33 to 76 years) underwent CABG without cardiopulmonary bypass. Single vessel disease was present in 46 (47.9%) patients, double vessel disease in 31 (32.3%), and triple vessel disease in 19 (19.8%) patients. All patients were operated through a standard midsternotomy and an optimal combination of pharmacological and mechanical methods were used to restrict cardiac movements during anastomosis. All patients underwent coronary angiography before discharge from the hospital. RESULTS: A total of 160 grafts were placed (range 1 to 4 grafts per patient, average 1.7+/-0.3 grafts per patient). A single graft was placed in 46 patients, double grafts in 38, triple grafts in 10, and quadruple grafts in 2 patients. Various grafts included pedicled left internal mammary artery (LIMA) (n = 95), free LIMA (n = 1), right internal mammary artery (n = 14), radial artery (n = 24), right gastroepiploic artery (n = 5), and saphenous vein grafts (n = 21). Operative mortality was 1.0% (1 of 96). Two patients required reoperation for excessive bleeding. Mean hospital stay was 5.7+/-1.2 days. Overall angiographic patency was 95.0% with LIMA patency of 97.9% (93 of 95). One patient with block in midsegment of LIMA was reoperated using cardiopulmonary bypass. Follow-up ranged from 4 to 17 months (mean 8.2+/-3.1 months). Two patients (one with narrowed LIMA to left anterior descending artery anastomosis, and one with patent anastomosis) had residual angina. CONCLUSIONS: Coronary artery bypass grafting without cardiopulmonary bypass is a reproducible, effective, and safe option in selected group of patients. A conscientious approach in patient selection and route of operation is required.

Ann Thorac Cardiovasc Surg. 1998 Jun;4(3):146-8.

Coronary artery bypass grafting without cardiopulmonary bypass.

Manjari R, Saha K, Jain A, Prasanna J, Singh J, Bhan A, Venugopal P, Das B.

Indraprastha Apollo Hospital, New Delhi, India.

Coronary artery bypass surgery on a beating heart is now an accepted modality to treat selected patients of ischaemic heart disease. From June '92 through Sep '97, 162 patients underwent this procedure. There was no mortality and none of the patients had any respiratory or neurological morbidity, though 24% of the patients form a high risk group for conventional coronary bypass surgery. It is definitely cost effective in comparison to any other modalities for treatment of ischaemic heart disease. We conclude that continous use of this technique is justified and all cardiac surgeons should have exposure to this procedure.

Int J Cardiol. 1991 May;31(2):155-9.

Profile of coronary arterial disease in diabetic patients undergoing coronary arterial bypass grafting.

Bhan A, Das B, Wasir HS, Kaul U, Venugopal P.

Department of Cardiothoracic and Vascular Surgery, All India Institute of Medical Sciences, New Delhi.

Diabetics are believed to have more extensive and diffuse lesions of the coronary arteries in presence of coronary arterial disease. We studied prospectively 52 diabetics with coronary arterial disease who underwent coronary arterial bypass grafting and evaluated their pre-operative symptomatology, angiographic appearance of coronary arteries, coronary arterial dimensions as assessed at surgery, and the post-operative complications. These were compared to 52 age and sex matched non-diabetic controls undergoing surgery during the same period. There was no statistically significant difference in the incidence of pre-operative symptomatology or frequency of myocardial infarction in the two groups. Left ventricular angiographic findings were also comparable, as was the observation on the extent and severity of coronary arterial disease as assessed by angiography and at surgery. Hence, we recommend coronary arterial bypass grafting to diabetics with the same criteria as are applied to non-diabetics, confident that there will be no added morbidity and mortality.

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