PubMed HealthSearch

Biomedical subjects

V G Tirlapur

Publications and source records attributed to V G Tirlapur.

18 recordsLinked to original sources

Cardiorespiratory effects of isosorbide dinitrate and nifedipine in combination with nadolol: a double-blind comparative study of beneficial and adverse antianginal drug interactions.

Combinations of 2 or 3 drugs are often used to treat angina pectoris, but their combined cardiorespiratory effects have not been investigated. Using a randomized, double-blind, placebo-controlled protocol, the effects of nadolol alone and nadolol in combination with isosorbide dinitrate and nifedipine were compared, in low and high doses, on antianginal efficacy, respiratory functions and arterial blood oxygen saturation (SaO2) in 19 patients with stable angina pectoris. A complete assessment including a bicycle exercise test with the measurement of the sum of ST-segment depression in all leads (sigma ST) was carried out every 2 weeks. The frequency of anginal attacks and nitroglycerin consumption was reduced significantly (p less than 0.001) by nadolol alone and in combination with the other drugs. Nadolol caused a slight reduction in the forced expiratory volume in 1 second, which was improved by isosorbide dinitrate and nifedipine. The sigma ST profile (basal, at peak exercise and 2 and 5 minutes after exercise) was decreased by nadolol alone and in combination with the other drugs, although the greatest reduction was achieved with large doses of nifedipine and nadolol. The rest and postexercise SaO2 decreased after nadolol alone and in combination with isosorbide dinitrate, but recovered to pretrial values after nifedipine and nadolol. With all drug combination, sigma ST depression was greater when the postexercise SaO2 was less than 92%, and decreased (p less than 0.05) in the same patients when their postexercise SaO2 was greater than 92%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists

Effect of low calorie intake on abnormal pulmonary physiology in patients with chronic hypercapneic respiratory failure.

To explore the effects of low calorie, low carbohydrate intake on abnormal pulmonary physiology in chronic hypercapneic respiratory failure, spirometric, arterial blood gas tension, oximetric, and electrocardiographic studies were carried out before and after weight reduction in eight patients. During a single night of monitoring, the mean basal oxygen saturation was 68.4 +/- 20.7 percent with 38 hypoxemic "dips" (a fall in oxygen saturation of more than 10 percent for one minute or longer); six patients had resting tachycardia, four had a prolonged QTc interval, three showed multiple episodes of ST-T depression, and six patients had multiple atrial and ventricular premature contractions. After a low calorie (600 kcal per day) intake for 4.4 +/- 2.3 weeks, there was a mean weight loss of 8.5 +/- 3.6 kg, the mean arterial oxygen tension increased significantly (p less than 0.005) from 55.6 +/- 9.2 to 69.1 +/- 7.9 torr, the mean arterial carbon dioxide tension fell from 59.9 +/- 9.6 to 52.4 +/- 5.4 torr (p less than 0.01), the mean oxygen saturation increased significantly (p less than 0.05) to 85.0 +/- 9.0 percent with only two hypoxemic "dips," the resting heart rate decreased from a mean of 100 +/- 19 to 90 +/- 18 beats/per minute (p less than 0.05), there was a marked reduction in ectopic activity, the ST-T depression disappeared, and the QTc interval fell in two subjects. Follow-up data in four patients suggest that the improvements achieved in arterial blood gas values can be maintained with a low calorie intake. These studies show that a low calorie, low carbohydrate intake improves all the unfavorable physiologic abnormalities in chronic hypercapneic respiratory failure.

Aged

Packed cell volume, haemoglobin, and oxygen saturation changes in healthy smokers and non-smokers.

We have investigated the relationship between cigarette smoking, packed cell volume, haemoglobin concentration, and arterial oxygen saturation (SaO2) in 114 non-smokers, 66 light smokers (1-20 cigarettes a day), and 50 heavy smokers (over 20 cigarettes a day) aged 20-75 years. Packed cell volume was greater in female heavy smokers (p less than 0.001) over 40 years of age and in all female smokers over 60 years (p less than 0.001) than in non-smoking contemporaries. Haemoglobin concentrations were higher in 40-59 year old female heavy smokers (p less than 0.05) and in male and female light (p less than 0.05) and heavy smokers (p less than 0.001) over 60 years of age than in non-smoking contemporaries. SaO2 was lower in 20-39 year old male heavy smokers (p less than 0.02) and female (p less than 0.05) light smokers and also in 40-59 year old male light and heavy smokers (p less than 0.001) and female light smokers (p less than 0.02) than in non-smoking contemporaries. It was also lower in female light (p less than 0.05) and heavy (p less than 0.02) smokers over 60 years, whereas it was higher in male light smokers over 60 (p less than 0.001). Changes in SaO2 were seen at a younger age than changes in haemoglobin concentration and packed cell volume.

Adult

A comparison of nifedipine and isosorbide dinitrate in angina pectoris with particular reference to arterial oxygen saturation.

To explore beneficial and harmful effects of various combinations of antianginal drugs, we compared antianginal and cardiorespiratory effects of nifedipine and isosorbide dinitrate in low and high doses in combination with nadolol, a long acting beta-adrenoceptor blocker in a double-blind study in 19 patients with stable angina pectoris. Nadolol alone and in combination with the other two drugs reduced anginal attack rate and glyceryl trinitrate consumption; the high dose isosorbide dinitrate showed a further significant (P less than 0.05) reduction in both but the high dose nifedipine did not show such a trend. sigma ST depression (all leads) was significantly (P less than 0.05) more reduced by the high dose nifedipine than by the same dose of isosorbide dinitrate in combination with nadolol. Nadolol reduced forced expiratory volume in one sec (FEV1) slightly and this effect was reversed both by isosorbide and nifedipine. Isosorbide dinitrate in combination with nadolol reduced the basal and post-exercise arterial oxygen saturation (SaO2) whereas nifedipine did not reduce the mean SaO2 below the pre-trial level. A significantly greater sigma ST depression was associated with a lower post-exercise SaO2 (less than or equal to 92%) during all treatment periods but the fall of SaO2 occurred more often during isosorbide than during nifedipine treatment periods. These studies show that both isosorbide dinitrate and nifedipine enhance antianginal efficacy of nadolol. Isosorbide dinitrate, unlike nifedipine, reduces SaO2 which is associated with a greater sigma ST depression.

Adrenergic beta-Antagonists

Nocturnal hypoxemia and associated electrocardiographic changes in patients with chronic obstructive airways disease.

To study the direct effects of nocturnal hypoxemia on the heart, we recorded electrocardiographic tracings and arterial oxygen saturation (SaO2) during the night in patients with chronic obstructive airways disease. In seven "blue-bloater" patients the mean basal SaO2 was less than 80 per cent, and it fell by more than 10 per cent during 29 episodes of transient hypoxemia. Only five such episodes occurred in three of five "pink-puffer" patients. All "blue bloaters" with low basal mean SaO2 had multiple atrial and ventricular premature contractions and a high heart rate at rest; six patients has a prolonged QTc, three had ST-T depression, and one had right-bundle-branch block. Oxygen therapy increased basal mean SaO2, reduced ectopic activity, abolished ST-T changes and bundle-branch block, significantly reduced the resting heart rate and the amplitude of the R and S waves, and shortened the QTc in four nonsmokers. These results suggest that sustained hypoxemia contributes to myocardial dysfunction and heart failure in "blue-bloater" patients.

Aged

Rehabilitation of the coronary patient.

52 out of 56 patients with myocardial infarction completed a 6-week rehabilitation programme. The exercise programme started on the second day of admission and continued during the patient's stay in hospital and for 6 weeks thereafter, with weekly attendances at the hospital. All the patients were assessed monthly by a coronary rehabilitation team. 77% of the patients went back to work in an average time of 9.5 weeks after onset of the infarction; 61% went to their original jobs and 16% had to modify their jobs. The approximate hospital cost per patient for the complete course was 11.33 pounds.

Adult