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Biomedical subjects

N K Prasad

Publications and source records attributed to N K Prasad.

At least 19 recordsLinked to original sources

Evaluation of guidelines for the use of telemetry in the non-intensive-care setting.

To determine if the American College of Cardiology (ACC) cardiac monitoring guidelines accurately stratify patients according to their risks for developing clinically significant arrhythmias in non-intensive-care settings, we conducted a prospective cohort study of 2,240 consecutive patients admitted to a non-intensive-care telemetry unit over 7 months. Sixty-one percent of patients were assigned to ACC class I (telemetry indicated in most patients), 38% to class II (telemetry indicated in some), and 1% to class III (telemetry not indicated). Arrhythmias were detected in 13.5% of the class I patients, 40.7% of the class II patients, and 12% of the class III patients (p <.001). Telemetry detected an arrhythmia resulting in transfer to an intensive care unit in 0.4% of the class I patients, 1.6% of the class II patients, and none of the class III patients (p =.006). Telemetry led to a change in management for 3.4% of the class I patients, 12.7% of the class II patients, and 4% of the class III patients (p <.001). When patients with chest pain as the reason for admission were moved from class I to class II and patients with arrhythmias as the reason for admission were moved from class II to class I, more arrhythmias and more clinically significant arrhythmias occurred in class I patients and the trends from class I to class III were more consistent with the purpose of the guidelines. These findings indicate that when the ACC guidelines are reexamined, consideration should be given to changing them so they are more useful in non-intensive-care settings.

Arrhythmias, Cardiac↗

Therapeutic preparations of normal polyspecific IgG (IVIg) induce apoptosis in human lymphocytes and monocytes: a novel mechanism of action of IVIg involving the Fas apoptotic pathway.

Therapeutic preparations of normal human IgG for i.v. use (i.v.Ig) exhibit a broad spectrum of immunoregulatory activities in vitro and in vivo. I.v.Ig has been shown to inhibit the proliferation of activated B and T lymphocytes and of several autonomously growing cell lines. In this study, we demonstrate that i.v.Ig induces apoptosis in leukemic cells of lymphocyte and monocyte lineage and in CD40-activated normal tonsillar B cells, involving, at least in part, Fas (CD95/APO-1) and activation of caspases. I.v.Ig-induced apoptosis was higher in Fas-sensitive HuT78 cells than in Fas-resistant HuT78.B1 mutant cells, and soluble Fas inhibited IVIg-induced apoptosis. I.v.Ig immunoprecipitated Fas from Fas-expressing transfectants and recognized purified Fas/glutathione-S-transferase fusion proteins upon immunoblotting. Affinity-purified anti-Fas Abs from i.v.Ig induced apoptosis of CEM T cells at a 120-fold lower concentration than unfractionated i.v.Ig. Inhibitors of cysteine proteases of the caspase family, caspase 1 (IL-1beta-converting enzyme) and caspase 3 (Yama/CPP32b), partially inhibited i.v.Ig-induced apoptosis of CEM cells. Furthermore, cleavage of poly(A)DP-ribose polymerase into an 85-kDa signature death fragment was observed in CEM cells following i.v.Ig treatment. Thus, normal IgG induces apoptosis in lymphocytes and monocytes. Our results provide evidence for a role of Fas, bring new insights into the mechanisms of action of i.v.Ig in autoimmune diseases, and suggest a role of normal Ig in controlling cell death and proliferation.

Animals↗

Role of telemetry monitoring in the non-intensive care unit.

To determine the outcomes of patients admitted to a non-intensive care telemetry unit and to assess the role of telemetry for guiding patient management decisions, data from 2,240 patients admitted to a telemetry unit were collected prospectively during 7 months. Physicians recorded the outcomes (intensive care unit transfer and mortality) and assessed whether telemetry assisted in guiding patient management. Indications for admission to the telemetry unit included chest pain syndromes (55%), arrhythmias (14%), heart failure (12%), and syncope (10%). Telemetry led to direct modifications in management in 156 patients (7%; 95% confidence interval [CI] 5.9% to 8%). Telemetry was perceived as useful but did not alter management for 127 patients (5.7%; 95% CI 4.7% to 6.6%). Two hundred forty-one patients were transferred to an intensive care unit from the telemetry unit (10.8%; 95% CI 9.5% to 12%). Nineteen patients (0.8% of all admissions; 95% CI 0.5% to 1.2%) were transferred because of an arrhythmia identified by telemetry. Routine transfer after cardiac revascularization or surgery accounted for 134 transfers; clinical deterioration accounted for 88 transfers. There were 20 deaths in the unit (0.9%; 95% CI 0.5% to 1.3%): 4 of the 20 deaths occurred while patients were being monitored. The role of telemetry in guiding patient management may be overestimated by physicians, since it detected significant arrhythmias that led to change in medications or urgent interventions in a small fraction of patients.

Aged↗

Outcomes of patients hospitalized to a telemetry unit.

To describe the clinical course of patients admitted to a nonintensive care telemetry unit and to determine whether telemetry identifies patients at risk for transfer to the intensive care unit (ICU), 467 patients hospitalized for cardiac monitoring in a nonintensive care telemetry unit were followed until death or discharge. The American College of Cardiology guidelines for telemetry use were applied: 65% of patients were class I (monitoring definitely indicated); 33% class II (probably indicated); and 2% class III (not indicated). In 5 patients (1%), telemetry contributed to the decision for a transfer to the ICU. In 462 patients, telemetry added no significant information. Thirty-eight patients (8.1%) were transferred to an ICU: 22 because of cardiac deterioration and 16 because of noncardiac clinical deterioration. Eighteen percent of patients in class I (95% confidence interval [CI], 14.1 to 22.8), 12% in class II (95% CI, 6.7 to 17), and none in class III (95% CI, 0 to 26) were transferred to the ICU (p = 0.03). Nine patients died (1.9%), 4 with terminal illness. Three patients died while on telemetry: 1 had metastatic lung cancer and 2 died suddenly of cardiac causes during initial evaluation on the ward. Telemetry identified the terminal rhythm in the 3 patients. Patients admitted to a non-ICU monitored ward with ischemic syndromes, heart failure, and arrhythmia rarely deteriorated. Patients who did deteriorate were recognized clinically without appreciable contribution from the monitoring process. It remains unproven that heart rhythm monitoring in general practice units improves patient care.

Arrhythmias, Cardiac↗

Assessment of impaired left ventricular diastolic function in patients with coronary artery disease, using radionuclide angiography.

Left ventricular (LV) diastolic filling at rest was assessed in 76 patients with coronary artery disease (CAD) and 16 healthy subjects using radionuclide angiography. Peak LV filling rate (PFR), expressed in end diastolic volume per second (EDV/sec), was subnormal in CAD patients (1.95 +/- 0.51 as compared to the normal 3.11 +/- 0.36, P < 0.001) and time to PFR (TPFR) was prolonged (171.1 +/- 79 msec versus 106.6 +/- 25 msec normal, P < 0.001). These indices were also abnormal in 60 patients with normal resting LV ejection fraction (PFR 2.17 +/- 0.48 EDV/sec, TPFR 163.9 +/- 68 msec). Abnormal LV filling at rest (PFR EDV/sec or TPFR 160 msec) was found in 88 percent of all patients with CAD, 85 percent of patients with normal resting LV ejection fraction, and 83 percent of patients without Q waves on resting electrocardiogram. Thus, LV diastolic filling, evaluated non invasively by radionuclide angiography, appears to be abnormal in a high percentage of patients with CAD independent of LV systolic function or previous myocardial infarction.

Adult↗

Association between cigarette smoking and coronary arterial disease in patients in India: how quantitative is it? An assessment by selective coronary arteriography.

With a view to study the association between smoking and coronary arterial disease, and to identify any quantitative relationship, we undertook a cross sectional analysis of 1105 consecutive male patients investigated by selective coronary arteriography to confirm or exclude coronary arterial disease. Pattern and distribution of disease were evaluated in 3 groups of patients who never smoked; who smoked less than 5 cigarettes per day; and who smoked 6 to 60 or more cigarettes per day. Suitable statistical tests, including adjusting for confounders, were carried out. The prevalence of disease was higher amongst smokers even after adjustment for confounders. The number of cigarettes smoked, and whether the smokers had quit, made no difference to the angiographic appearance or extent of disease. There was no difference in the distribution and severity of disease amongst smokers and non-smokers. Rate ratio of disease amongst smokers in India was higher in those patients between 26 and 45 years of age than in other age groups. Smoking could be identified as a risk marker/risk factor that accelerated the disease process in those prone to develop the disease. It may be advantageous to initiate public health and preventive measures directed specifically at the group aged between 26 to 45 years, and later to address all others who smoke.

Adult↗

Labetalol and nifedipine in the management of essential hypertension.

Antihypertensive effects of labetalol and nifedipine were evaluated in a double blind cross over trial in ambulatory patients with moderately severe hypertension (mean diastolic BP 101.2 +/- 1.78 mm Hg, 105 +/- 2.15 mm Hg respectively and mean systolic BP 164.2 +/- 4.2 mm Hg and 171.4 +/- 5.82 mm Hg respectively in each group of 10 patients). The effect of labetalol over the systolic and diastolic BP was highly significant (p less than 0.01). The effects of nifedipine on systolic and diastolic BP were also significant but effects on diastolic BP was highly significant (p less than 0.01). In cross over study it was seen that nifedipine was not much superior in lowering the systolic BP whereas diastolic BP was lowered to a significant level (p less than 0.05) as compared to labetalol.

Blood Pressure↗

A study of lipid levels in Indian patients with coronary arterial disease.

A detailed cross-sectional analysis of total cholesterol and triglyceride levels was studied in 1066 consecutive male patients who underwent selective coronary arteriography in our centre to confirm or exclude coronary arterial disease. There were 877 cases of coronary arterial disease and 189 patients with normal coronary arteries. Besides descriptive statistics of lipid levels in different age groups, percentile distribution was studied. Association characteristics between lipids and other risk factors was studied by multiple regression analysis. Relative risk of lipids, controlling for the confounding variable of age as well as weight was obtained using the Mantel Haenszel chi square procedure. Results revealed the occurrence of coronary artery disease with low lipid levels in our population. The 50th percentile for total cholesterol was 205 mg/dl for the cases and 186 mg/dl for controls, while for triglycerides it was 158 mg/dl for cases and 140 mg/dl for controls. Multiple regression analysis of smoking, positive family history, diabetes, hypertension, weight and age contributed a low R square value of 2.49% for cholesterol and 4.22% for triglycerides in the cases and controls. The Mantel Haenszel chi square test procedure confirmed that low lipid levels could be seen irrespective of the age or weight of individuals. It is speculated that other factors which may include ageing, metabolic or immunologic components yet to be ascertained, could contribute additionally, to atherosclerotic coronary arterial disease in our population.

Adult↗

Electrocardiographic left atrial enlargement--correlation with echo.

To assess the utility of electrocardiogram in identifying left atrial enlargement, electrocardiogram of 600 consecutive patients were correlated with their M-mode echocardiographic findings. Left atrial enlargement, as reflected by P terminal force in V1 had sensitivity of 79%, specificity 91%, predictive value 85% and accuracy of 86%. Patients older than 30 years with large left atrium (greater than 5.0 cm) had atrial fibrillation more frequently than younger patients (P less than 0.001). It is concluded that P terminal force in V1 is a reliable indicator of left atrial enlargement.

Adult↗

Severity of mitral regurgitation in mitral valve prolapse syndrome. A Doppler echocardiographic study.

Thirty-three consecutive patients with mitral valve prolapse with a systolic murmur were evaluated using pulsed doppler echocardiography to quantify the severity of mitral regurgitation. There were thirteen (39%) patients with mild regurgitation, twelve patients (36%) with moderate regurgitation and eight patients (24%) with severe regurgitation. It was noticed that, all the patients with severe regurgitation had posterior leaflet prolapse. In contrast, patients with anterior leaflet prolapse had either mild or moderate regurgitation only. Our results suggest that the degree of mitral regurgitation differs depending on the leaflet that shows the prolapse, which may be of importance in the followup of patients with mitral valve prolapse.

Adult↗

Phase analysis of radionuclide ventriculograms in patients with coronary artery disease.

Phase analysis of radionuclide ventriculograms were performed in eighty patients with coronary artery disease (CAD) and in sixteen healthy subjects. The phase image in the normal group revealed a homogeneous pattern and a narrow bell shaped histogram. In forty one patients with CAD whose Left ventriculogram showed hypokinetic segments, phase image was abnormal in twenty six revealing well demarcated areas of contraction abnormality and a histogram showing broad base with multiple peaks. The mean phase angle and the standard deviation (S.D.) of phase histogram of the abnormal segments was significantly different from normal. Eighteen patients with CAD had akinetic segments. Phase analysis was abnormal in all. Six patients with CAD had dyskinetic segments. It is concluded that phase image analysis is very useful in detecting segmental wall motion abnormalities.

Adult↗

Dipyridamole radionuclide ventriculography for localisation of coronary artery disease.

Nineteen consecutive patients who had coronary arteriography underwent dipyridamole stress testing with 0.14 mg/kg/min infusion over 4 minutes during computer assisted radionuclide ventriculography. Global ejection fraction, diastolic function and regional ejection fraction were calculated by a semiautomatic method. There were 17 patients with severe left anterior descending disease of which 12 involved the proximal segment of the LAD, 15 patients with left circumflex disease and 13 patients with right coronary artery disease. Abnormalities in resting or stress induced regional ejection fraction was used for localisation of severe coronary artery disease. The overall sensitivity was 75 per cent with a specificity of 75 per cent, a positive predictive value of 90 per cent and a negative predictive value of 45 per cent. For LAD disease the sensitivity was 94 per cent with a 100 per cent specificity while proximal segment of LAD had a sensitivity of 100 per cent and a specificity of 57 per cent. Identification of left circumflex disease had a sensitivity of 47 per cent and a 100 per cent specificity and right coronary artery had a 85 per cent sensitivity and a 50 per cent specificity. Four patients developed ST changes, 6 developed chest discomfort and 1 patient developed giddiness. All 7 were promptly reversed with intravenous aminophylline. Thus dipyridamole radionuclide ventriculography is a highly sensitive and specific method for localisation of CAD.

Adult↗