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Biomedical subjects

B Bharadwaj

Publications and source records attributed to B Bharadwaj.

At least 37 records · Page 2Linked to original sources
PubMed1988

Intraoperative Doppler flow studies: emphasis on colour mapping.

Colour Doppler flow imaging (CD) is a well-established method of assessing valvular and congenital disease of the heart. The technique has proven useful intraoperatively in patients undergoing valve repair or replacement or intracardiac reconstruction. In 21 patients with various cardiac anomalies, colour Doppler flow imaging was used intraoperatively, before cardiac cannulation and again after cardiopulmonary bypass. Previously undisclosed features were demonstrated preoperatively in two patients and important residual defects after cardiopulmonary bypass in three others. Adequacy of valve replacement was confirmed in four patients and small leaks in ventricular septal defect patches were shown in another three. The procedure facilitated repair of complex cardiac fistulas in two patients. There were no apparent complications from CD. As intracardiac repairs become more complex, the role of intraoperative CD will expand.

Adult↗
PubMed1988

Traumatic wound of the heart: value of intraoperative colour Doppler flow imaging.

A patient who sustained a traumatic ventricular septal defect from a stab wound is presented. Intraoperative echo-Doppler imaging provided an additional diagnosis of avulsion of anterior papillary muscle of the tricuspid valve prior to cardiotomy. It was concluded that intraoperative echo-Doppler imaging proves a useful guide for cardiac surgery following penetrating trauma.

Adult↗
PubMed1987

Right atrial myxoma presenting as Budd-Chiari syndrome.

A 25-year-old man experienced rapidly progressing Budd-Chiari syndrome. Despite extensive radiological investigations, no atrial mass could be identified. At operation, a right atrial myxoma was found that originated from the eustachian valve and prolapsed into the inferior vena cava. Following successful removal of the myxoma, the ascites and peripheral edema resolved completely. Right atrial myxoma is a rare cardiac tumor that may present with embolic, obstructive, or constitutional signs and symptoms and is a potentially curable cause of Budd-Chiari syndrome.

Acute Disease↗
PubMed1987

Effect of crystalloid cardioplegia and verapamil on cardiac function and cellular biochemistry during hypothermic cardiac arrest.

A study was undertaken to assess the effectiveness of cold crystalloid cardioplegia with or without verapamil on the functional recovery of the heart, Ca++ binding and uptake, Ca++ ATPase of sarcoplasmic reticulum, sarcolemmal ATPase and the MB fraction of creatine kinase (MBCK) after 1.5 h of reperfusion following 1 h of ischemic cardiac arrest. The dogs were divided into three groups: group I, sham bypass; group II, cold crystalloid cardioplegia; group III, cold crystalloid cardioplegia with verapamil. There was a decrease in the cardiac index (CI), left ventricular work index (LVWI) and mean aortic pressure (MAP) in the sham bypass group at the end of the protocol (time period corresponding to 60 mins off bypass). There was a decrease in the Cl and index of myocardial contractility in the cold crystalloid cardioplegic group compared to sham bypass group. The decrease in the cardiac function in cold crystalloid group was associated with a decrease in Ca++ uptake by sarcoplasmic reticulum and a tendency for an increase in the sarcolemmal Na+-K+ ATPase. The Ca++ binding and the Ca++ ATPase of sarcoplasmic reticulum were not affected. The index of myocardial contractility and cardiac function were better with cold crystalloid containing verapamil than with cold crystalloid alone. This improvement, although partial, in cardiac contractility and function with cold crystalloid cardioplegia containing verapamil was associated with an improvement in the Ca++ uptake by the sarcoplasmic reticulum. The Ca++ ATPase and Ca++ binding were depressed in group III. The MBCK in systemic and coronary sinus blood increased progressively in groups II and III. Although there was an increase in MBCK in group I the increase was not significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphatases↗
PubMed1985

Effect of prazosin treatment on the cardiac sarcolemmal ATPase in failing heart due to mitral insufficiency in dogs.

Prazosin has been used in the treatment of congestive heart failure. It is, however, not known whether prazosin gives only haemodynamic benefit or if it also produces a decrease in the cardiac sarcolemmal Na+-K+-ATPase which has been reported to be increased in the failing heart. The present investigation deals with the effect of 3 months of prazosin treatment in dogs with 3 months of induced mitral insufficiency (MI) on the sarcolemmal Na+-K+-ATPase activity. The dogs were divided into four groups each comprising of five dogs. A--normal; B--3 months of MI; C--6 months of MI; D--3 months of prazosin treatment after 3 months of MI. Three months of MI produced a decrease in the dp/dt and an increase in the end-diastolic pressure of left ventricle but no change in the index of left ventricular contractility and cardiac index. Also there was no change in the sarcolemmal Na+-K+-ATPase. There was a significant decrease in the index of left ventricular contractility and cardiac index and an increase in the LVEDP associated with a significant increase in the left ventricular sarcolemmal Na+-K+-ATPase at 6 months of MI. Sarcolemmal Mg2+-ATPase of both ventricles increased after 6 months of MI the significance of which is not known as yet. There was no change in the sarcolemmal Na+-K+-ATPase of the nonfailing right ventricle. Prazosin treatment prevented the deterioration of the left ventricular contractility and function and also prevented the increase in the sarcolemmal Na+-K+-ATPase observed in failing heart.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphatases↗
PubMed1985

Effect of chronic prazosin treatment on the cardiac function and electrolytes in failing heart due to chronic mitral insufficiency.

The effect of three months of prazosin treatment on the hemodynamics, cardiac extracellular space; plasma, tissue and intra-cellular Na+, K+, and Ca++ were investigated in dogs with left ventricular failure due to chronic mitral insufficiency. Mitral insufficiency of 6 months duration significantly decreased the LV systolic pressure, LV dp/dt, LV (dp/dt)/IIP, LVWI, CI, and increased the LVEDP, mean right atrial pressure, heart rate and systemic vascular resistance. Associated with these hemodynamic changes were an increase in the extra-cellular space, tissue and intracellular K+; and a decrease in the tissue and intracellular Ca++. Prazosin treatment produced an improvement in the hemodynamics which was associated with a decreased in the extracellular space, and intracellular K+, and an increase in the intracellular Ca++. Plasma Na+ and Ca++ increased with 6 months of M.I. Prazosin treatment brought back the plasma Na+ and K+ to control level. However, plasma Ca+ decreased significantly with prazosin treatment. The changes in right ventricular hemodynamics and electrolytes were not consistent with the right ventricular failure. These results indicate that decrease in the myocardial contractility in chronic heart failure due to mitral insufficiency might be due to a decrease in the intracellular Ca++. Prazosin treatment was able to reverse the hemodynamic and electrolyte changes induced by failing heart due to mitral insufficiency.

Animals↗
PubMed1984

Mitral valve replacement in the neonate: a report of two cases.

Mitral valve replacement was performed in two critically ill neonates with severe mitral stenosis and regurgitation. Both patients had coexisting severe aortic stenosis previously treated by transventricular aortic valve dilatation. Preoperative echocardiography showed a mitral annulus measuring between 11 and 12 mm in diameter--too small for any of the commercially available free-standing valve prostheses. Accordingly, the porcine valve from a commercially available 12-mm external-valved conduit was removed and sutured into position. The function of the valve was satisfactory in both cases and cardiopulmonary bypass was discontinued easily with a good cardiac output established in both. Both patients died--one at 20 h and one 36 h after surgery. In each case, the immediate cause of death was acute bleeding secondary to preexisting hepatic failure and depletion of coagulation factors. At autopsy, both prostheses had been correctly placed and were competent. Left ventricular outflow tract obstruction secondary to strut imposition was not evident. Both patients were very ill preoperatively. Although neither patient survived mitral valve replacement, we were encouraged by the relative hemodynamic improvement in the immediate postoperative period. We believe that prosthetic valve replacement could become a viable therapy for the neonate with severe mitral valve abnormalities.

Aortic Valve↗
PubMed1984

Saccular aortic aneurysm in an asymptomatic child.

An asymptomatic boy was found to have coarctation of the thoracic aorta. Despite no history of endocarditis or trauma, a large saccular aneurysm involving the coarctation site was identified angiographically, confirmed, resected surgically, and examined histologically.

Aortic Aneurysm↗
PubMed1984

Effects of chronic digoxin treatment on cardiac function, electrolytes, and sarcolemmal ATPase in the canine failing heart due to chronic mitral regurgitation.

This study was designed to determine whether digoxin therapy in the canine heart failing because of mitral regurgitation (MR) provides only hemodynamic benefit and accompanying subjective improvement or if it also reverses the changes in intracellular Ca++ and sarcolemmal Na+-K+-ATPase. The dogs were divided into four groups: control, MR of 3 months' duration, MR of 6 months', and digoxin treatment for 3 months after 3 months of MR. Six months of MR produced a marked decrease in the index of myocardial contractility and function associated with a decrease in intracellular Ca++ and Na+, and an increase in intracellular K+, extracellular space, sarcolemmal Na+-K+-ATPase, and Mg++-ATPase. Digoxin treatment tended to return the changes in the index of myocardial contractility and cardiac function, intracellular Ca++, Na+, K+, extracellular space, and sarcolemmal Na+-K+-ATPase of the failing heart toward control levels. Digoxin treatment did not affect Mg++-ATPase. The right ventricle, which did not fail, also did not show any significant changes in the parameters measured. The results showed that digoxin treatment not only improved the index of myocardial contractility and cardiac function of the failing heart but also tended to return the electrolytes and sarcolemmal Na+-K+-ATPase toward control levels.

Animals↗
PubMed1984

Effect of chronic digoxin treatment on cardiac function, electrolytes and ATPase in failing heart due to pressure overload.

A decrease in the cardiac function and intracellular calcium, and an increase in the cardiac sarcolemmal ATPase have been reported in aortic stenosis of 6 to 9 months duration in dogs. The present investigation deals with the effect of 3 months of digoxin treatment on cardiac function, electrolytes and ATPase in dogs with 3 months of aortic stenosis in order to determine whether digoxin treatment gives only haemodynamic improvement or if it also improves the condition of the myocardium in terms of contractility and biochemical changes. There were no significant changes in any of the haemodynamic parameters of left and right ventricles except the left ventricular end-diastolic pressure which increased significantly at 3 months of aortic stenosis. All the hearts developed left ventricular hypertrophy. Concomitant with these changes, there was a tendency for a decrease in the total tissue Ca2+, intracellular Ca2+ and K+, and a tendency for an increase in the sarcolemmal ATPase. There were no significant differences in any of the haemodynamic parameters between the aortic stenotic and digoxin treated aortic stenotic dogs indicating that digoxin was at least maintaining the haemodynamics close to the pretreatment level. Although digoxin treatment prevented the changes in the sarcolemmal ATPase and extracellular space, it did not prevent the further decrease in the total or intracellular Ca2+. The total and intracellular Ca2+ was still significantly higher than previously observed after 6 to 9 months of aortic stenosis. These results suggest that digoxin treatment not only tended to prevent further deterioration of cardiac function but also tended to prevent further changes in the sarcolemmal ATPase and electrolytes.

Adenosine Triphosphatases↗
PubMed1984

Effect of prolonged prazosin treatment on hemodynamic and biochemical changes in the dog heart due to chronic pressure overload.

A decrease in cardiac function and intracellular calcium, and an increase in cardiac sarcolemmal ATPase have been reported in experimentally induced aortic stenosis of 6 to 9 months duration. Prazosin has been used in the treatment of heart failure due to mechanical ventricular overload. It is, however, not known whether prazosin treatment gives only hemodynamic benefit with accompanying subjective improvement or if it also improves the condition of the myocardium in terms of contractility and biochemical changes. The present investigation deals with the effects of 3 months of prazosin treatment on cardiac function, electrolytes, and ATPase in dogs with aortic stenosis of 3 months duration. Although there were no significant changes in most of the left and right ventricular hemodynamic parameters, the left ventricular end-diastolic pressure increased significantly after 3 months of aortic stenosis. Prazosin prevented further deterioration of cardiac function. All the dogs developed left ventricular hypertrophy and all chest X-rays showed cardiomegaly. Concomitant with these changes, there was a tendency towards a decrease in total tissue Ca++ and intracellular Ca++ and K+ and a tendency towards an increase in sarcolemmal Na+-K+-ATPase. Prazosin treatment, although it markedly reduced left ventricular end-diastolic pressure, did not reduce the cardiomegaly. There were no significant changes in any of the other hemodynamic parameters. Prazosin treatment decreased sarcolemmal ATPase and tended to increase intracellular Ca++. It appears therefore that prazosin not only tends to bring the cardiac function towards control values but also tends to correct the ATPase and intracellular Ca++ levels of the failing heart.

Animals↗
PubMed1980

Effects of enflurane on cardiovascular function in dogs with induced chronic mitral valve disease.

The effect of enflurane on cardiovascular function was investigated in normal dogs and in dogs with chronic heart failure because of induced mitral valve disease (MVD). No significant changes were observed in heart rate (HR), right atrial pressure (RAP) and total systemic vascular resistance (TSVR) in normal dogs. However, significant decreases in HR and increases in RAP and TSVR were observed in dogs with MVD. There were no changes in pulmonary arterial pressure and left ventricular end-diastolic pressure in either group. Cardiac output, cardiac index, arterial pressure, left ventricular work index and left ventricular dp/dt and dp/dtIIP showed a concentration-dependent decrease in both groups but the changes were greater in dogs with MVD.

Anesthesia, Inhalation↗
PubMed1980

Long-term follow-up of patients who underwent single valve replacement with Björk-Shiley prosthesis.

Single heart-valve replacement with a Björk-Shiley prosthesis was undertaken in 118 patients between Jan. 3, 1970 and Dec. 31, 1977. The hospital mortality was 7% for patients who had aortic valve replacement and 9% for those who had mitral valve replacement. Recent improvements in techniques for myocardial preservation and cardiopulmonary bypass resulted in a notable reduction in hospital mortality during the period 1974 to 1977 compared with that in the period 1970 to 1973; the rate was 5% for aortic valve replacement and 4% for mitral valve replacement between 1974 and 1977 compared with 9% and 18%, respectively, during the period 1970 to 1973. There was an additional late mortality of 8% in patients who had an aortic valve replaced and 11% in those who had a mitral valve replaced; the mean follow-up was 2.3 years (range 6 months to 7.5 years). Seventy-one patients with an aortic valve prosthesis and 38 patients with a mitral valve prosthesis were alive at the time of late follow-up. In patients who received an aortic valve prosthesis, 73% had an excellent result after operation (New York Heart Association classes I or II) and 18% had some functional improvement. In patients who received a mitral valve prosthesis, 68% had an excellent result and 18% were functionally improved after operation. The incidence of thromboembolism was 8.3% and of anticoagulant-related complications, 13.8%.

Adult↗
PubMed1980

Metabolic response to cardiopulmonary bypass using a Bentley oxygenator.

The present investigation deals with the blood gases, serum lactic acid, serum and urine electrolytes, and urea and creatinine before, during, and after cardiopulmonary bypass. This study was conducted with 25 patients. There were significant increases in PO2, PCO2, HCO3-, serum creatinine, urine potassium, and urine chloride. However, there were no significant changes in serum sodium, potassium, chloride, blood pH, lactic acid, urea and urine creatinine, urine urea, urine index, and urine Na+ during cardiopulmonary bypass. On the first postoperative day there were significant increases in PCO2, HCO3-, serum creatinine and urea, urine creatinine, urea, potassium and chloride, and significant decreases in the blood pH and urine index. Other measured parameters did not change significantly. Most of the measured parameters returned toward normal within 5 days except for decreases in serum chloride and sodium and increases in urine, urea, and potassium. These results indicate that the use of a Bentley oxygenator during cardiopulmonary bypass does not affect the biochemical parameters adversely.

Blood Gas Analysis↗
PubMed1979

Intra- and extracellular electrolytes and sarcolemmal ATPase in the failing heart due to pressure overload in dogs.

An investigation of changes in the Mg2+ -dependent, Na+ -K+ -stimulated sarcolemmal ATPase and of intracellular electrolytes in the left failing heart due to pressure overload (aortic banding) was carried out in dogs. There was no change in the sarcolemmal Mg2+ -ATPase of the left or right ventricle for the whole duration (3 to 9 months) of left ventricular pressure overload. In the early phase (3 months) of aortic banding, when there was no haemodynamic evidence of left ventricular failure, there was also no significant change in the sarcolemmal Na+ -K+ -ATPase, extracellular space, or intra- and extracellular electrolytes. However, during 6 to 9 months of aortic binding when there was haemodynamic evidence of left ventricular failure (increased end-diastolic pressure, decreased cardiac index and (dP/dt)/IIP, enlarged heart), there was also a marked increase in the left ventricular sarcolemmal Na+ -K+ -ATPase and intracellular K+; and a decrease in the intracellular Na+ and Ca2+. The extracellular space in the left ventricle also increased significantly. Unlike the left ventricle, the right ventricle did not show any evidence of failure, not did it show any change in the sarcolemmal Na+ -K+ -ATPase and intracellular electrolytes during any period of aortic banding. These results suggest that the decrease in the myocardial contractility in failing heart due to pressure overload might be associated with a decrease in the intracellular Ca2+ as a result of an increase in the sarcolemmal Na+ -K+ -ATPase.

Animals↗
PubMed1978

Alterations in red cell metabolism during and following cardiac bypass surgery.

Reduced concentrations of red cell organic phosphates and increased hemoglobin--oxygen affinity have been reported during and following cardiac bypass surgery. Some have related these changes to low concentrations of ATP and 2,3-diphosphoglycerate (DPG) in stored blood while others have related them to use of the pump oxygenator. There was a 10% decrease in DPG concentration in seven dogs on cardiac bypass although the animals received no transfusions. In 16 patients who received 0 to 7 units of blood during cardiac bypass there was a decrease of 10% in the red cell DPG concentration from the preoperative value, but it did not relate to the concentration of DPG in the transfused blood bags. The magnitude of the decrease was not sufficient to impair oxygen delivery severely. The results suggest that a re-evaluation of indications for the use of fresh red cells in cardiac surgery is necessary.

Adenosine Triphosphate↗