Valvular heart disease: diagnosis and management.

Valvular heart disease is a leading cause of morbidity and mortality in India. Advances in both surgical and percutaneous techniques and a better understanding of timing for intervention accounts for the current increased rates of survival. Echocardiography remains the gold standard for diagnosis and periodic assessment of patients with valvular heart disease. Generally, patients with stenotic valvular lesions can be monitored clinically until symptoms appear and most can now benefit from percutaneous techniques. In contrast, patients with regurgitant valvular lesions require careful echocardiographic monitoring for left ventricular function and may require surgery even if no symptoms are present. Percutaneous therapy of valvular regurgitant lesions is yet to evolve fully.

Endocarditis due to Chryseobacterium meningosepticum.

Chryseobacterium meningosepticum is a gram negative rod widely distributed in nature. It is known to cause meningitis in neonates and premature infants. Adult infections are not common and are usually nosocomially acquired. We report an unusual case of native valve endocarditis in a 58-year-old man due to this organism. A high degree of suspicion and correct identification and sensitivity testing is required to diagnose infections by this rare isolate.

Prevalence of cardiovascular risk factors in Indian patients undergoing coronary artery bypass surgery.

BACKGROUND: Conventional cardiovascular risk factors (CVRFs) are known to influence short-term and long-term outcome following coronary artery bypass graft surgery (CABG). There has been recent increase in prevalence of CVRFs in general population in India. However no information is available regarding the prevalence of same in patients undergoing CABG. METHODS AND RESULTS: In this cross-sectional study, one thousand consecutive patients undergoing elective CABG were included and data on major CVRFs was obtained in them. Mean age of the patients was 59.73 +/- 9.5 years and 884/1000 (88.4%) patients were males. 505/994 (50.8%) patients had BMI > or = 25.0 kg/m2 and 747/994 (75.2%) had BMI > or = 23.0 kg/m2. Diabetes mellitus was present in 475/1000 (47.5%) patients (46.5% men and 55.2% women), hypertension in 709/1000 (70.9% overall; 70.8% men and 71.6% women) and dyslipidemia in 781/913 patients (85.6% overall; 84.5% men and 93.9% women). 213/913 (23.3%) patients had LDL > or = 100mg/dl, 662/913 (72.5%) patients had low HDL and 338/913 (37.0%) patients had elevated triglycerides. 199/1000 (19.9%) patients (18.7% men and 29.3% women) had family history of premature CAD and 545/1000 (54.5%) patients (53.4% men and 62.9% women) had at least one family member having CAD (irrespective of the age of onset). 94/1000 (9.4%) patients (10.4% men and 1.7% women) were current smokers and another 302/1000 (30.2% overall; 33.7% men and 3.4% women) had history of smoking in the preceding one year. 876/913 (95.9%) of all the patients had at least one of the five major CVRFs and only 37/ 913 (4.1%) patients (4.1% men and 4.3% women) were free of all these risk factors. Sixty-one of the 1000 patients (6.1%) were younger than 45.0 years of age. As compared to older patients, dyslipidemia, family history of premature CAD and smoking were commoner in patients less than 45 years of age. In contrast, diabetes and hypertension were more prevalent in the older individuals. CONCLUSIONS: The present study showed high prevalence of most of the conventional CVRFs, esp. diabetes, hypertension and dyslipidemia in Indian population undergoing CABG.

Robotically enhanced coronary artery bypass surgery.

BACKGROUND: Robotically enhanced telemanipulation surgery is a fast developing technique which allows totally endoscopic cardiac surgery with utmost precision and perfection on both beating heart as well as arrested heart. METHODS AND RESULTS: Between December 2002 and February 2004, 125 patients underwent robotically enhanced coronary artery bypass surgery using the da Vinci telemanipulation system (Intuitive Surgical Inc., California). Eleven patients underwent totally endoscopic coronary artery bypass surgery. Of them 9 were done on beating heart while 2 were done on arrested heart. One hundred and fourteen patients had endoscopic takedown of internal mammary artery followed by minimally invasive direct coronary artery bypass in 63 patients and left anterolateral thoracotomy in 51 patients. The internal mammary artery mobilization time was 42 min (35-74 min) while the left internal mammary artery to left anterior descending artery anastomosis time ranged from 20 to 36 min for the totally endoscopic coronary artery bypass patients. In 1 patient, the right internal mammary artery was anastomosed to diagonal artery totally endoscopically. The mean internal mammary artery flow by Doppler measurement done in patients undergoing minimally invasive direct coronary artery bypass was 64 ml/min. Seven patients required conversion to median sternotomy and coronary bypass surgery on beating heart. The mean intensive care unit stay was 1.2 days and the mean hospital stay 4.5 days. There was 1 in-hospital mortality. All 11 patients who underwent totally endoscopic bypass surgery had coronary angiography done at 3 months interval which showed 100% patency in 10 patients while one patient had 50% anastomotic narrowing for which coronary angioplasty was done in the same sitting. CONCLUSIONS: Using telematic technology, a complete endoscopic anastomosis is possible in both single vessel and suitable double vessel disease patients. The use of robotics is now extended to achieve complete myocardial revascularization by harvesting both the internal mammary arteries and making a small thoracotomy for direct anastomosis as well.

Is off-pump coronary artery bypass surgery safe for left main coronary artery stenosis?

BACKGROUND: The feasibility of off-pump coronary artery bypass surgery has been well demonstrated. The purpose of the present study was to assess the safety and efficacy of off-pump coronary artery surgery in patients with left main coronary artery disease. METHODS AND RESULTS: Between January 1997 and December 2000, 174 patients with significant left main coronary artery stenosis underwent coronary artery bypass grafting without a pump. During the same period, 991 patients who also had significant left main coronary artery stenosis underwent coronary artery surgery on a pump. The patients in the two groups were matched in preoperative variables except that those in the off-pump group were slightly older, and more required urgent surgery. Hospital mortality was 2/174 and 21/991 in the off-pump and on-pump groups, respectively (p=0.560). The incidence of perioperative myocardial infarction (1.74 v. 14/991, p=0.712), atrial fibrillation (17/174 v 157/991, p=0.050) and blood transfusion requirement (63/174 v. 476/991, p=0.05) were significantly less in the off-pump group. The intubation time (15+/-3 hours v 22+/-4 hours, p=0.001), blood loss (365+/-61 ml v 582+/-76 ml, p<0.001), intensive care unit stay (23+/-10 hours v. 36+/-11 hours, p<0.001) and hospital stay (6+/-4 days v. 9+/-5 days, p <0.001) were also less in the off-pump group. CONCLUSIONS: Off-pump coronary artery bypass surgery is safe and effective for patients with left main coronary artery disease.

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.

Carotid endarterectomy under regional analgesia:a retrospective study (1988-1999).

The procedure of carotid endarterectomy is more or less standardized. Controversies persist on many technical issues, one of which is general versus regional anaesthesia. We retrospectively evaluated the influence of regional analgesia on perioperative complications, the hospital stay and the perioperative mortality after carotid endarterectomy in 53 patients. All the patients in the study received deep cervical block regional anaesthesia (Winne's technique) for carotid endarterectomy. Indications for surgery included transient ischaemic haemodynamically significant stenosis. Shunt was used in 7 cases (13.2%). General anaesthesia was supplemented in 2 patients (3.8%). There was no perioperative mortality. Permanent non-fatal neurologic deficit occurred in 1 patient (1.9%) and temporary neurologic Deficit occurred in 1 patient (1.9%). The mean ICU stay was 1.85 (+/-0.82) days and the hospital stay was 5.2 (+/-1.14) days. On the basis of our data we believe that under regional anaesthesia carotid endarterectomy can be performed with acceptable complications and that regional anaesthetic technique is safe and well tolerated by the patients.

Changes in transfusion therapy guided by thromboelastograph in cardiac surgery.

This study was conducted to determine the use of thromboelastograph in predicting excessive postoperative bleeding, detecting coagulopathy related bleeding, reducing usage of blood and blood products and aiding reexploration decisions. One hundred fifty patients undergoing coronary artery bypass graft surgery under cardiopulmonary bypass were randomized and studied prospectively in two equal groups. In the study group, celite activated heparinase pretreated blood samples, 30 minutes after protamine administration were subjected to thromboelastographic analysis and blood and blood component therapy was administered based on thromboelastograph values, if they had significant bleeding. In the control group transfusion therapy was based on routine coagulation tests and clinical judgement of the surgeon. Patients who bled 100ml / hour in the first three hours or 300 ml in the first three hours and 75 ml/hour in the next three hours were considered significant bleeders. Haematocrit at 0,6,12,18,24,30 and 36 hours of shifting to intensive care unit were noted. Accuracy of thromboelastograph in predicting excess postoperative bleeding was found to be 92%. Consumption of whole blood, packed red blood cells and fresh frozen plasma (p values 0.03, 0.05, 0.001 respectively) was significantly less in the study group. There was poor correlation between postoperative bleeding and platelet count but those who did not bleed had a significantly higher platelet count as compared to those who did. Except at 30 hours, haematocrit was significantly higher in the study group up to 36 hours. Thromboelastograph is a useful diagnostic tool to detect coagulopathies following cardiopulmonary bypass. It helps in instituting appropriate blood and blood component therapy thereby avoiding unnecessary transfusion and associated risks. Accurate detection of coagulopathy is possible with heparinase pretreatment of the blood sample.

Mechanical ventilation in the prone position: a strategy for acute respiratory failure after cardiac surgery.

Ventilation in the prone position, initially introduced in respiratory therapy to improve the drainage of secretions, has been used in intensive care to improve oxygenation. We report a case of an obese male patient who underwent elective coronary artery bypass grafting and had low PaO2 in the postoperative period. The PaO2 improved whenever the patient was ventilated in the prone position. On each occasion, oxygenation improved without any change in the hemodynamic parameters. The PaO2 increased from 57.8 to 249.7 mmHg on the first occasion, from 48.7 to 194.6 mmHg on the second and 62.5 to 199.7 mmHg on the third at an FIO2 of 1.0. The shunt fraction (Qva/Qt) decreased from 43.6% to 7.2% on the first occasion and from 46.7% to 12.5% on the second. Ventilation in the prone position can be an effective method for improving oxygenation in patients suffering from postoperative acute respiratory failure who are not responding to other ventilatory strategies.

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.

Efficacy of reiki on patients undergoing coronary artery bypass graft surgery.

Reiki was administered to 50 patients out of 100 patients with normal left ventricular function scheduled for elective coronary artery bypass grafting. Blood components and inflammatory markers were estimated at various time points. Haemodynamic parameters, psychological analysis, intensive care unit stay,incidence of infection, chest tube drainage and mortality were recorded. Haemodynamic parameters and use of blood components were similar in both groups. Interleukin-6 were significantly lower in the preoperative period in the Reiki group, but showed similar trends in both the groups in the post-operative period. The psychological analysis assessed by World Health Organisation quality of life and General Health Questionnaire revealed that social relationships improve once patient is in his own surroundings and with his own people in both the groups. Psychological domain showed significant difference, six day after surgery in the Reiki group. This study concludes that Reiki is a time consuming process with no significant clinical benefit.

Propofol -fentanyl anaesthesia: a comparison with isoflurane-fentanyl anaesthesia in coronary artery bypass graft surgery.

The haemodynamic effects of propofol -fentanyl anaesthesia (n=25) were compared with isoflurane-fentanyl anaesthesia (n=25) in patients with normal left ventricular ejection fraction (>45%) undergoing coronary artery bypass graft surgery under cardiopulmonary bypass. In the propofol group (Group P), anaesthesia was induced with midoazolam 2.5 to 5.0 mg, fentanyl 5mg/kg, pancuronium 0.1 mg/kg and propofol 1-2 mg/kg and was maintained with propofol infusion 10 mg/kg/hr till sternotomy, followed by 3 mg/kg/hr till skin closure. In the inhalational group (Group I) anaesthesia was induced with midazolam, fentanyl, pancuronium in the same doses and sleep dose of thiopentone and was maintained with oxygen : nitrous oxide (50:50) and isoflurane (0.5-1%). Additional fentanyl 2.5 microg/kg was given before sternotomy. Haemodynamic measurements were made before induction, after induction, after sternotomy, after heparinisation, after release of aortic cross clamp, post-bypass, post-sternal closure and on arrival in the recovery room. Post-bypass the cardiac index was higher in Group P (2.90+/- 0.76 v/s 2.40 +/- 0.40, p <0.05). Similarly post-bypass stroke volume index was higher in Group P (379.32 +/- 6.31 v/s 26.78 +/- 6.24, p<0.05). Patients in Group P were extubated earlier as compared to Group I (379.50 +/- 69 min v/s 453.00 +/- 134 min, p<0.05). This study suggests that propofol may be a suitable adjunct to opioid anaesthesia in patients with normal left ventricular ejection fraction undergoing coronary artery bypass graft surgery.

Sevoflurane for induction and intubation in children undergoing congenital cardiac surgery.

The induction and intubation characteristics of sevoflurane were studied prospectively in 23 children, aged 3 months to 6 years (mean 24 +/- 20.25), undergoing repair of congenital cardiac defects. After premedication with syrup chloral hydrate (75mg/kg orally), anaesthesia was induced with 8% sevoflurane and 50% nitrous oxide in oxygen. Nasal endotracheal intubation was performed once the pupils were small and central, without the use of neuromuscular blocking agents or opioids. Characteristics of induction and intubating conditions were recorded. Induction time (from application of face mask to loss of eyelash reflex) was 43.7 +/- 4.57 secs (mean +/- SD). Mean intubation time was 149.1 +/- 15.6 secs. Intubating conditions were excellent in 21 patients (91.3%) and good in 2 patients (80.7%). Haemodynamic parameters (heart rate, rhythm, and systolic blood pressure) were recorded at loss of eyelash reflex, immediately before intubation and at 1, 3 and 5 min after intubation. All children remained haemodynamically stable throughout induction and there were no adverse airway events.

Minimally invasive atrial septal defects repair.

This study reviews the current method of atrial septal defect closure at our institute with a minimally invasive approach without median sternotomy. From September 1997 to August 1998, 37 patients (13 males, 24 females) with mean age 36.5 years (range 18-67 years) underwent atrial septal defect closure by right anterior thoracotomy. Femoral vessels were cannulated through a small groin incision and extracorporeal circulation was established. Venous drainage was assisted with a centrifugal pump. Aortic crossclamping was performed through the intact chest wall using a special transthoracic clamp with sliding rod design inserted through a separate tiny 3 mm incision in the right second intercostal space in the mid clavicular line. Mean duration of cardiopulmonary bypass and aortic crossclamp time was 35 +/- 14 and 23 +/- 7 minutes respectively; mean endotracheal intubation time after surgery 6.2 +/- 3 hours; mean ICU stay 10.6 +/- 2.8 hours; mean length of thoracotomy incision 7.2 +/- 1.8 cm; and, mean hospital stay 4.2 +/- 1.8 days. There was no post-operative neurological dysfunction or femoral cannulation related complication. There was no perioperative or late mortality. No residual atrial septal defect was observed by transoesophageal echocardiography in any patient. The procedure described here provides secure closure of the atrial septal defects in minimally invasive fashion with good results.