Transthoracic electrical bioimpedence cardiac output: comparison with multigated equillibrium radionuclide cardiography.

INTRODUCTION: Thoracic electrical bioimpedance (TEB) for measuring cardiac output (CO) is being explored increasingly as an alternative to pulmonary artery catheter. The major advantage of this technology is that it is non-invasive and easy to perform. Several studies have compared it to thermodilution cardiac output using PA catheter, with variable correlation. Multigated radionuclide equilibrium cardiography (RNEC) method of cardiac output measurement is known to be reliable. OBJECTIVE: To compare cardiac output measured by thoracic electrical bioimpdenace with that measured by multigated radionuclide equilibrium cardiography. PATIENTS AND METHODS: CO studies were performed sequentially at a single sitting by TEB and RNEC methods among patients with cardiac symptoms referred for radionuclide study as part of their evaluation. TEB CO was measured by placing two pairs of electrodes on either side of neck and two other pairs on either side of the lower chest. Stroke volume was estimated from the sequential changes in transthoracic electrical bioimpedance induced by rhythmic aortic blood flow, using Kubicek equation. RNEC-CO was measured by intravenous injection of radio-active Technitium-tagged RBCs followed by ECG gated blood pool imaging over the chest (MUGA study). Bland-Altman analysis was used to compare the measurements. RESULTS: A total of 32 subjects with proven or suspected ischemic heart disease, but without overt cardiac failure, edema or arrhythmias were studied (M:F::26:6; mean age: 48 +/- 12 years). The mean TEB-CO was 3.54 +/- 1.052 l/min and mean RNEC-CO was 3.907 +/- 0.952 l/min. Correlation coefficient (r) for these measurements was 0.67 (p < 0.01), with bias: -0.421 l/min; precision: 1.557 l/min; and percentage error of measurement: 42.35%. CONCLUSIONS: This study observed a moderate correlation between TEB and RNEC methods of CO measurement. Further studies are indicated to explore the relative utility of TEB in comparison with RNEC as well as other methods of CO measurement before considering its use in patients with ischemic heart disease.

Non-invasive cardiac output by transthoracic electrical bioimpedence in post-cardiac surgery patients: comparison with thermodilution method.

OBJECTIVE: Thoracic electrical bioimpedance (TEB) cardiac output (CO) is being explored increasingly as a non-invasive alternative to the pulmonary artery catheter (PAC). This study compared TEB-CO measured using a new instrument--NICOMON (Larsen & Toubro Ltd. India) with thermodilution (Td) CO in post-cardiac surgery patients. METHODS: Postoperative cardiac surgical patients requiring a PAC for their management were studied. TEB-CO was measured by passing a 4 mA RMS alternating current across the chest and measuring the analog bioimpedence across the thorax. Kubicek equation was used to estimate TEB-CO. Td-CO was measured using a PAC. Bland-Altman analysis was used to compare paired data. RESULTS: One hundred and ninety-seven pairs of CO measurements were made by the two methods among 35 patients. Mean TEB-CO was 5.15 +/- 1.27 l/min and mean Td-CO was 5.22 +/- 1.28 l/min. Pearson correlation coefficient (r) for these measurements was 0.856 (P < 0.01), with bias -0.0651 l and precision: +/-1.37 l/min. The percentage error of measurement of this precision was 26.44%. Cardiac index also correlated among the two methods (r = 0.789; P = 0.01). CONCLUSIONS: Thoracic electrical bioimpedance cardiac output compares favorably with thermodilution method among post-cardiac surgery patients. Further studies are indi- cated with this instrument to validate its efficacy in various clinical situations and utility in monitoring hemodynamic interventions.

Valve replacement in the young patient with rheumatic heart disease. Review of a twenty-year experience.

During a 20-year period 303 young subjects between 9 and 20 years of age (mean, 16.2 +/- 2.72 years) with rapid and relentlessly progressive valvular disease from rheumatic fever underwent valve replacements. The Starr-Edwards ball valve prosthesis remains the device of choice, although other valves have been implanted. The overall hospital mortality rate was 9.6% in the mitral valve, 3.5% in the aortic valve, and 4.2% in the double valve replacement groups. Actuarial survival at 10, 15, and 20 years was 78.4% (+/- 3.3%), 70.0% (+/- 5.8%), and 59.3% (+/- 11.1%), respectively, for patients with mitral valve replacement. The rates for aortic valve replacement were 85.9% (+/- 4.6%) at 10 and 15 years and 72.7% (12.8%) at 20 years. In the double valve replacement group the survival rates after 5 and 10 years were 79.9% (+/- 5.1%). The incidence of thromboembolism was 0.41, 0.59, and 1.04 per 100 patient-years for the mitral, aortic, and double-valve prostheses, respectively. The prospect of childbearing seems promising in those young women who were subsequently married. Our favorable and gratifying experience in this review bears testimony to the physiologic advantages of the Starr-Edwards valve as the device of choice in the rehabilitation of patients with advanced and severe valvular disease after rheumatic fever.

The profile and surgical management of mitral stenosis in young patients.

Mitral stenosis in the younger age groups in India is a unique condition characterized by a short duration and a rapid progression of symptoms. The majority of patients with this lesion develop pulmonary hypertension at an accelerated pace, and about one third have associated congestive failure and functional tricuspid regurgitation. Five hundred consecutive patients with this condition were treated surgically, 493 with a closed valvotomy. The over-all hospital mortality rate of 5.8 per cent was related to the severity of the preoperative functional status. In the last 150 cases, the figure dropped to 2 per cent. Assessment during the first 5 years after surgery revealed an excellent functional status in 85 per cent. The incidence of restenosis was only 3.4 per cent in the first 5 year period and 11 per cent in a subsequent 6 to 10 year follow-up period. Twenty of the 21 subjects with restenosis had an excellent functional result following closed transventricular valvotomy, and this status has been maintained during the follow-up period. To our knowledge, there are no other reports of long-term follow-up data in young patients undergoing surgical treatment for mitral stenosis.

Mitral valve replacement in the young patient with rheumatic heart disease. Early and late results in 118 subjects.

During a 14 year period, 118 young patients between 9 and 20 years of age underwent mitral valve replacement. In view of the acknowledged advantage of durability and minimal thrombogenicity, we chose the Starr-Edwards valve prosthesis in the large majority of our subjects. Other prostheses have also been used. Hospital mortality has been only 3% in the past 5 years. Frail, severely incapacitated children and adolescents have had an impressive spurt in growth and weight and have returned to normal activities. Nine of the patients have had a normal pregnancy and have borne children. The remarkable clinical improvement has been corroborated by hemodynamic benefit. Follow-up over a period 1 to 15 years (mean 5.09 +/- 3.3) showed a very low incidence of embolic phenomena. In Third World countries, rheumatic heart disease continues to be a daunting challenge with pronounced disability resulting in death. Mitral valve replacement in the young subject with significant rheumatic valve disease should not be delayed until severe pulmonary vascular changes and myocardial damage pose a major deterrent.

The adult ductus: review of surgical experience with 131 patients.

Results in patients over 14 years of age who have undergone surgical closure of a patent ductus arteriosus during the period 1967 through 1979 have been reviewed. There were 131 subjects (average age 22 years) with a slight male predominance, which is at variance with other reports. Sixty-two subjects underwent hemodynamic evaluation and of these, 30 had pulmonary artery pressures ranging from 50 to 150 mm Hg. Division and suture of the ductus with aortic cross-clamping under normothermic conditions was performed in 61 subjects. This approach was particularly indicated in cases in which the ductus was unusually short in relation to its diameter as well as in many with atheromatous changes at the aortic end. In 65 subjects, the conventional division and suture with ductus clamps was employed. Total cardiopulmonary bypass with transaortic patch closure of the ductus was carried out in three instances. There were five early deaths which were principally associated with severe pulmonary hypertension. During a follow-up period extending from 1 to 11 years, three subjects died, but the remainder are well and active. Recatheterization data in nine patients with severe pulmonary hypertension showed gratifying results.

Development of a coagglutination (COA) technic to detect Candida antigenemia. I. COA versus Candida isolation.

A coagglutination (COA) test to detect Candida antigenemia was developed using locally produced Candida antiserum and COA reagent. All 68 controls had normal results. Two patient groups were included in this study. In Group 1, consisting of eight patients, with definite systemic or deep candidiasis proved by repeat Candida isolation, COA detected antigenemia in 100% as against 50% by counterimmunoelectrophoresis (CIE). In Group 2, 9 of 19 patients had respiratory infection; 4 patients revealed antigenemia by COA, 2 of whom had no Candida isolation. In these 2 patients therapy was initiated based on COA results. Of another nine patients with hematologic and malignant diseases, five (56%) revealed antigenemia by COA, three of whom had no Candida isolation; two died and one was discharged against advice. Transient antigenemia was detected by COA in a single patient with ulcerative colitis with Candida isolation. Thus, the COA test was found to be rapid, sensitive, and specific for the detection of Candida antigenemia. Furthermore, it had early diagnostic (seven days) as well as prognostic value, as revealed by response to therapy and decrease in COA titer. Being highly cost effective, this test is recommended as a simple test within the reach of any routine diagnostic laboratory.

Massive left atrial thrombus complicating mitral stenosis with atrial fibrillation: results of surgical treatment.

Thirty-five patients with massive atrial thrombus complicating mitral stenosis and atrial fibrillation were treated surgically. The mean age in this series is lower than that reported in the West. Furthermore, the incidence of preoperative embolic manifestations has been less frequent in our experience. We believe it is desirable to document the presence of a thrombus by selective left atrial cineangiography. Surgical treatment was accomplished with an acceptable mortality. The vital role played by the use of low-molecular-weight dextran and early anticoagulation in decreasing the incidence of postoperative cerebral embolism is emphasized. Follow-up data in the survivors has shown excellent functional status with no late embolic phenomena in any subject.

Surgical treatment of ruptured aneurysms of the sinus of Valsalva.

Aneurysms of the sinus of Valsalva are usually congenital in origin. When they rupture, it is generally into the right atrium or the right ventricle. Signs of a left-to-right shunt, aortic runoff, and cardiac decompensation are the cardinal features. Early diagnosis and surgical correction result in cure. We report our experience with 28 patients. In all patients, we used a combined aortocameral approach, and we recommend a sandwich patch for the repair. Aortic valve replacement is needed only in patients with severe degenerative changes. The overall operative mortality was 21.4%, but in the last 10 years, mortality was only 11.7%. The causes of operative and late mortality are discussed.

Restenosis of the mitral valve: surgical considerations and results of operation.

Our experience over an eight-year period with 63 consecutive patients with mitral restenosis who underwent operation forms the basis for this report. Striking clinical disability was a notable finding. A majority of the patients were less than 30 years old. Embolic phenomena were rare. Closed transventricular valvotomy offers excellent low-risk palliation and good long-term results. Follow-up showed excellent or good results in 90.5% of the patients and poor results in 9.5%. Hemodynamic study of 6 patients demonstrated a pronounced decrease in the pulmonary artery pressure. Open valvotomy was performed in 6 subjects. The presence of intracardiac calcification together with mild mitral incompetence in 2 patients made valve replacement mandatory. The problem of restenosis of the mitral valve is complex, and only after further long-term results are available will the superiority of any one method be demonstrated.

Chest malignancies & serum immunoglobulin E.

Serum IgE levels were measured by the radioimmunoassay technique in the sera of 53 patients with neoplastic chest diseases. Forty seven patients had malignant chest tumours and another 6 had benign tumours or mediastinal cysts. They included 33 smokers and 20 non-smokers. For comparison, 30 normal non-smoking controls matched for age and sex were included. The serum IgE levels in patients with chest malignancies showed an increase as compared to controls. The IgE levels increased significantly in adenocarcinoma (P < 0.01) and squamous cell carcinoma (P < 0.001), while they were not raised in poorly differentiated carcinoma. There was no significant difference between the serum IgE levels of 32 smokers and 15 non-smokers with malignant chest tumours.

Interrupted aortic arch with tetralogy of Fallot. A report of an unsuccessful surgically treated case.

Interrupted aortic arch is a complete discontinuity of two segments of the aorta. Although associated with a number of conditions, it does not occur in association with pulmonary stenosis. We report a case unsuccessfully treated but from which we have learnt a lesson.

Total anomalous pulmonary venous return in children and adults. Results of corrective surgery.

The operative technique and the early and long term results are described in twenty consecutive patients who have undergone corrective surgery for total anomalous pulmonary venous return over a 12 year period from 1967 to 1979. There was a 15 per cent early mortality which occurred only in children below the age of four. There have been no late deaths. All survivors are leading normal gainful lives. Nine of seventeen have been recatheterised. The abnormality when encountered in children and adults carries a more favourable prognosis than when encountered during infancy.

Closed mitral valvotomy in the older subject. Results in 367 consecutive patients.

To determine the safety, efficacy, operative mortality, and long-term results, we reviewed 367 patients with mitral stenosis above the age of 40 who underwent mitral valvotomy. In this study, the majority of the subjects belonged to functional Class III and IV (97%) of the New York Heart Association (NYHA). Atrial fibrillation was associated in 38 percent and mitral valve calcification in 24 percent. The hospital mortality was 6.3 percent. Only 1 patient developed severe mitral regurgitation requiring emergency valve replacement. Early postoperative embolism occurred in only 1% of those who were in atrial fibrillation and had preoperative anticoagulation. Long-term results indicate an 85.6 percent survival at the end of 24 years with a very low incidence of restenosis. Late death occurred in 4.6%. These findings support our continuing experience and impression that closed transventricular valvotomy remains the most effective palliative operation in the treatment of most patients with mitral stenosis. With the increasing need for cost containment in health care, this technique of closed transventricular valvotomy assumes even greater importance.

Aortic valve replacement in India. Early and long term results.

Experience with 261 subjects undergoing aortic valve replacement is presented. The mean age of our patients (29.6 years) is much less an compared to reports from the West. History of rheumatic fever was obtained in 53%. Aortic regurgitation was documented in 72.7% of our subjects whilst the remainder had calcific aortic stenosis. The left ventricular and diastolic pressure was elevated in 24% and the systemic index was less than 3 l/min/m2 in 71%. Associated mitral stenosis was present in 31 subjects (11.8%) who had concomitant open mitral valvotomy. The Starr-Edwards ball valve model 1260 was utilised in the great majority (76.6%). The overall hospital mortality was 9.9% which had decreased to 4.5% during the last five year period. Poor myocardial protection leading to low cardiac output occurring in class IV subjects was the cause of death in most instances. All survivors were followed up for periods ranging from 1 to 12 years (mean 4.2). Thrombo-embolic phenomenon occurred in 1.6 per 100 patient years and the incidence of paravalvar leak has been extremely low (0.4%). This is in striking contrast with reports from other authors. Actuarial analysis at the end of 5 years and 10 years indicates overall probability of survival of 92.9% and 92.2% respectively.

Iliac aneurysmo-colonic fistula. A case report and review of literature.

A case of a 47 year old man with an aneurysmo colonic fistula is presented. This rare complication presents problems in diagnosis and management. The presentation of this case and operative management without the use of a graft is discussed along with a review of literature.

A bypass technique for aneurysms of descending aorta.

Uniformity of opinion does not exist regarding optimal surgical strategy for descending aortic aneurysms. We present a surgical technique for bypass during aortic cross clamp while operating on such aneurysms. Five patients have undergone surgery using this technique. All of them are alive, doing well with no complications.

Surgical management of coarctation of aorta.

Between 1961 and 1988, 68 patients underwent operation for coarctation of the aorta. The average age of presentation of these subjects was higher than in other series. 7.1 percent were asymptomatic, a finding which is not seen in reports from the west. Operative procedures included resection and end to end anastomosis, resection and graft interposition, bypass grafting, patch aortoplasty and subclavian flap aortoplasty. However, the technique of patch aortoplasty, routinely performed in the last 24 years of this series seemed by far the most satisfactory procedure. Subclavian flap aortoplasty was carried out in a selected group of younger children. Associated cardiac anomalies influenced the results adversely. The overall operative mortality was 5.8 percent. Hypertension did not regress in 11.7 per cent of patients inspite of a successful operation as judged by the return of peripheral pulses in the lower limbs. Re-coarctation was not seen in this series. The overall results of operation for coarctation of the aorta have been very satisfactory and comparable with those in other published series.

Constrictive pericarditis and its surgical management.

The surgical management of 66 cases of constrictive pericarditis has been presented. Tuberculosis was the most common etiologic factor in this series. The importance of optimal myocardial function has been emphasized. Pericardiectomy was limited to release of the ventricles in order to correct the hemodynamic anomaly. The vast majority of patients claimed to have benefited from surgery.

Giant emphysematous bullae of the lung.

Emphysematous bullae may at times assume large proportions. We report a case of symptomatic giant bullae in a female which were removed surgically. The relevant literature has also been reviewed.