Discrete subvalvular aortic stenosis in adults.

Discrete subvalvular aortic stenosis is a relatively rare condition in adults. It is often diagnosed during first decade of life especially in association with other congenital malformations. Isolated form of discrete subvalvular aortic stenosis may however silently progress from innocent murmurs of childhood and adolescence to symptomatic left ventricular outflow tract obstruction in adults. Certain overt and subtle morphological abnormalities may underlie the initial expression as well as high recurrence rates after surgical resection of sub aortic membrane. Though surgical resection is the only treatment available, debate on the surgical technique and appropriate timing of surgery continues. Close followup with serial echocardiographic examinations in patients detected to have functional murmurs during childhood may be helpful in early detection of subvalvular aortic stertosis.

Discrete subvalvular aortic stenosis.

Discrete Subaortic Stenosis is one of the many lesions responsible for left ventricular outflow tract (LVOT) obstruction. It may present as in an isolated from as membranous or fibromuscular ring below the aortic valve or in association with other congenital anamolies such as VSD, PDA, coarctation of aorta, hypoplastic aortic annulus, double chamber right ventricle among others. The condition is rarely diagnosed antenataly or in infancy but often manifests in the first decade of life with features of progressive LVOT obstruction, LV hypertrophy and dysfunction aortic regurgitation due to damage to the aortic cusps because of the jet from the subaortic narrowing which may also render the aortic valve prone to infective endocarditis. Interaction of genetic predisposition and morphologically deformed long and narrow LVOT cause rheological abnormalities and increased shear stress in the region of subaortic stenosis and seem to be the main etiological factor alongwith poorly defined role of more extensive but subtle changes in the LV endocardium. Condition can be easily diagnosed by cross-sectional and Doppler echocardiography and confirmed by demonstrating a pressure gradient below aortic valve on cardiac catheterisation and LV angiography. Surgical membranectomy alongwith myotomy or myomectomy remain the mainstay of treatment but long term results are not satisfactory as there is a high rate of recurrences requiring reoperations. A close follow up with serial echocardiographic examinations is very helpful in early detection of subaortic obstruction in patients who have so called functional murmurs in the childhood.

Coronary artery bypass surgery without cardiopulmonary bypass: short- and mid-term results.

From March 1994 to April 1997, 433 patients had undergone coronary artery bypass grafting without cardiopulmonary bypass in our institute. Sixty-eight patients had various organ dysfunctions and/or aortic atheroma or calcification and were regarded as high risk for cardiopulmonary bypass. In 277 patients surgery was performed through midline sternotomy, while in 156 minithoracotomy approach was used. In 361 patients single coronary artery bypass grafting was done, and in 72 two-coronary arteries were bypassed. In 63 patients who had graftable vessels in anterior wall and diffusely diseased ungraftable vessels in posterolateral and/or inferior wall, transmyocardial laser revascularisation was also done along with coronary artery bypass grafting to achieve complete myocardial revascularisation. Nine patients in this series were also subjected to simultaneous carotid endarterectomy along with myocardial revascularisation. In two patients complementary percutaneous transluminal coronary angioplasty of left circumflex coronary artery was done five days after minithoracotomy and left internal mammary artery to left anterior descending coronary artery bypass grafting. Forty-two cases were extubated in operating room. Average blood loss was 260 ml. Six patients were reexplored for postoperative bleeding. Seven patients had perioperative myocardial infarction. One developed neurological complication. Hospital mortality was 2.3 percent (10/433 cases) and four deaths were due to malignant ventricular arrhythmias. Nine patients developed chest wound complications. Average hospital stay after operation was six days, 423 patients were discharged from hospital and all of them were asymptomatic. During three years follow-up (range 3 to 38 months) there were three known cardiac deaths. Ninety percent (391) patients reported to the follow-up clinic and 91 percent of them were angina-free. In patients who were subjected to transmyocardial laser revascularisation along with coronary artery bypass grafting, myocardial perfusion scan showed a step-wise improvement in reversible ischemia. The perfusion index increased from 52 percent at three months to 90 percent at 12 months. We conclude that coronary artery bypass grafting without cardiopulmonary bypass can be done with relatively low mortality, more so in a group of patients in whom cardiopulmonary bypass poses a high risk. Transmyocardial laser revascularisation is a suitable means to provide complete myocardial revascularisation along with coronary artery bypass surgery in patients who have graftable vessels in anterior wall and ungraftable vessels in posterolateral and inferior walls.

Transmyocardial laser revascularisation as an adjunct to CABG.

Transmyocardial laser revascularisation (TMLR), a new technique in which the ischaemic myocardium is perfused via laser-created transmural channels, was performed in 116 patients at the Escorts Heart Institute. TMLR was combined with CABG in 104 of these patients. The main indication for the combined procedure was the presence of one or more bypassable vessels along with diffuse disease in the other vessels. The age of the patients ranged from 37 to 73 years. Preoperatively, 53.84 percent of patients had Canadian Cardiovascular Society (CCS) class III angina while 24 percent had class IV angina. The mean LVEF was 46 percent; however, 19 percent of the patients had LVEF < 35 percent. Thirteen patients were operated upon a beating heart without cardiopulmonary bypass. The early mortality was 2.88 percent, 7.69 percent of patients showed elevation in CPK-MB, while 5.76 percent had a rise in Troponin 'T' and 2 percent of patients showed ECG changes. The mean follow-up was 7.6 months. Myocardial perfusion scan showed a step-wise improvement in reversible ischaemia, the perfusion index increasing from 52 percent at 3 months to 91 percent at 12 months. At 12 months, 91.6 percent of patients were angina-free. The Karnofsky score of 46 percent at baseline also increased to 86 percent at 12 months.

Bacteremia and bacterial infections in highly febrile children without apparent focus.

To find the incidence of bacteremia and serious bacterial infections in febrile children without an apparent focus of infection, we prospectively studied 100 febrile children aged 1 month-3 years with a rectal temperature > or = 39 degrees C. Ten children had a blood culture positive bacteremia and nine had serology positive for bacteremia; 6 had urinary tract infection, 5 otitis media and 8 meningitis. A diagnosis of non bacterial illness was made in 62 patients. Staphylococcus aureus was the most common bacteriologic isolate on blood culture (five) and by serology (eight). TLC > or = 15,000/cu mm m-ESR > or = 25 mm and temperature > or = 39 degrees C had high specificity (95-100%) but low sensitivity for diagnosis of bacteremia.