PubMed Health⌕ Search

Biomedical subjects

R J Northcote

Publications and source records attributed to R J Northcote.

At least 19 recordsLinked to original sources
PubMed2006

Hospital volume of throughput and periprocedural and medium-term adverse events after percutaneous coronary intervention: retrospective cohort study of all 17,417 procedures undertaken in Scotland, 1997-2003.

OBJECTIVE: To determine whether percutaneous coronary intervention (PCI) hospital volume of throughput is associated with periprocedural and medium-term events, and whether any associations are independent of differences in case mix. DESIGN: Retrospective cohort study of all PCIs undertaken in Scottish National Health Service hospitals over a six-year period. METHODS: All PCIs in Scotland during 1997-2003 were examined. Linkage to administrative databases identified events over two years' follow up. The risk of events by hospital volume at 30 days and two years was compared by using logistic regression and Cox proportional hazards models. RESULTS: Of the 17,417 PCIs, 4900 (28%) were in low-volume hospitals and 3242 (19%) in high-volume hospitals. After adjustment for case mix, there were no significant differences in risk of death or myocardial infarction. Patients treated in high-volume hospitals were less likely to require emergency surgery (adjusted odds ratio 0.18, 95% confidence interval (CI) 0.07 to 0.54, p = 0.002). Over two years, patients in high-volume hospitals were less likely to undergo surgery (adjusted hazard ratio 0.52, 95% CI 0.35 to 0.75, p = 0.001), but this was offset by an increased likelihood of further PCI. There was no net difference in coronary revascularisation or in overall events. CONCLUSION: Death and myocardial infarction were infrequent complications of PCI and did not differ significantly by volume. Emergency surgery was less common in high-volume hospitals. Over two years, patients treated in high-volume centres were as likely to undergo some form of revascularisation but less likely to undergo surgery.

Aged↗
PubMed1999

Cardiac assessment of veteran endurance athletes: a 12 year follow up study.

OBJECTIVES: Sustained aerobic dynamic exercise is beneficial in preventing cardiovascular disease. The effect of lifelong endurance exercise on cardiac structure and function is less well documented, however. A 12 year follow up of 20 veteran athletes was performed, as longitudinal studies in such cohorts are rare. METHODS: Routine echocardiography was repeated as was resting, exercise, and 24 hour electrocardiography. RESULTS: Nineteen returned for screening. Mean (SD) age was 67 (6.2) years (range 56-83). Two individuals had had permanent pacemakers implanted (one for symptomatic atrial fibrillation with complete heart block, the other for asystole lasting up to 15 seconds). Only two athletes had asystolic pauses in excess of two seconds compared with seven athletes in 1985. Of these seven, five had no asystole on follow up. Two of these five had reduced their average running distance by about 15-20 miles a week. One athlete sustained an acute myocardial infarction during a competitive race in 1988. Three athletes had undergone coronary arteriography during the 12 years of follow up but none had obstructive coronary artery disease. Ten of 19 (53%) had echo evidence of left ventricular hypertrophy in 1997 but only two (11%) had left ventricular dilatation. Ten athletes had ventricular couplets on follow up compared with only two in 1985. CONCLUSIONS: Although the benefits of moderate regular exercise are undisputed, high intensity lifelong endurance exercise may be associated with altered cardiac structure and function. These adaptations to more extreme forms of exercise merit caution in the interpretation of standard cardiac investigations in the older athletic population. On rare occasions, these changes may be deleterious.

Aged↗
PubMed1991

Metabolic parameters: how important are pharmacologically-induced changes?

It has been suggested that beta-blockers do not significantly reduce the frequency of coronary disease in hypertensives because they adversely affect the plasma lipoprotein profile. Non-selective beta-blockers cause a significant elevation of triglycerides and a reduction in the level of high-density lipoprotein. Cardioselective beta-blockers have similar, but less marked, effects. The non-selective beta-blockers with intrinsic sympathomimetic activity have little effect on the lipid profile, yet these are the least effective in reducing coronary mortality after myocardial infarction. Elevated blood flow velocity and high catecholamine levels can damage the vascular endothelium. This leads to increased permeability and the deposition of lipids. Beta-blockers reduce peak blood velocity and decrease the activity of catecholamines in plasma, which should reduce endothelial damage and the subsequent formation of plaques. Studies in animals have indeed shown that beta-blockers reduce the level of atherosclerosis, despite an elevation of serum lipids.

Adrenergic beta-Antagonists↗
PubMed1990

The effect of habitual sustained endurance exercise on cardiac structure and function.

We performed echocardiographic evaluation of 20 male veteran endurance runners (mean age 56 +/- 7 years) and compared them with a group of age-matched controls. All the runners had run at least 25 miles per week for more than 25 years. Although only four athletes showed voltage ECG evidence of left ventricular hypertrophy, using echocardiography, 10 athletes had evidence of left ventricular hypertrophy. Thus electrocardiography is insufficiently sensitive to detect LVH in this group (10%). Left ventricular posterior wall thickness and left ventricular mass were significantly greater in the athletes, the difference becoming more marked when LV mass was corrected for body surface area and, consequently, the wall thickness: cavity diameter ratio was increased (P less than 0.04). There was no difference between the two groups in left ventricular performance and no correlation between left ventricular mass and running ability. Thus, veteran runners develop structural cardiac changes similar to younger power-trained athletes and do not show characteristics normally expected of 'volume overload' which is thought to occur in running.

Blood Pressure↗
PubMed1989

Electrocardiographic findings in male veteran endurance athletes.

Twenty male veteran endurance runners and 20 controls underwent resting, exercise, and ambulatory electrocardiography. Four athletes and three controls satisfied voltage criteria for left ventricular hypertrophy. The PR interval was longer in the athletes and they had longer mean (SD) treadmill exercise times (19 (4) v 16 (2) min) than the controls. Four athletes but no controls had greater than 2 mm downsloping ST segment depression during exercise. During 48 hour ambulatory electrocardiography the athletes had a consistently lower heart rate but maintained a circadian variation. Profound bradycardia (less than 35 beats/min) occurred in eight athletes but only one control. Eight athletes and two controls had asystolic pauses ranging from 1.8 to 15 seconds. Six athletes had first degree heart block, four had Mobitz II second degree block, and three had complete heart block. Most conduction abnormalities occurred at night and resolved during exercise. Ventricular ectopic activity was not significantly different between the groups. Thus heart block patterns and profound bradycardia are more frequent in older athletes than their youthful counterparts.

Age Factors↗
PubMed1988

Left ventricular function and beta-blockers: does intrinsic sympathomimetic activity have any influence during chronic therapy?

A study comparing the chronic effects of propranolol (n = 21) and pindolol (n = 19) on male patients with stable angina pectoris was performed. Left ventricular function was assessed by serial radionuclide ventriculography. Radionuclide ventriculography was performed at rest and during cold pressor test. Both drugs improved symptoms of angina pectoris by at least one division of the New York Heart Association classification. Cold pressor testing caused increases in heart rate and blood pressure in both groups throughout the study. At rest, pretreatment ejection fraction was similar in both groups. During propranolol treatment this rose sequentially from 49% to 55% at 26 weeks. No change in the resting ejection fraction occurred in those taking pindolol. The difference in response between the groups reached significance at 26 weeks. In those with subnormal left ventricular ejection fraction (less than 50%), resting ejection fraction improved significantly throughout treatment with propranolol rising from a basal value of 39% to 51% at 26 weeks. In comparison, pindolol caused no significant change. There is no apparent advantage to intrinsic sympathomimetic activity in terms of preservation or improvement of left ventricular performance in patients with stable angina pectoris prescribed beta-blockers for extended periods of time.

Adrenergic beta-Antagonists↗
PubMed1988

The influence of beta-adrenoceptor blockers with and without intrinsic sympathomimetic activity on heart rate, arrhythmias and ST-T segments, using ambulatory electrocardiography.

1. Ambulatory electrocardiography was used to compare the effects of propranolol and pindolol on symptoms, heart rate, arrhythmias and ST segments. Seventeen males (mean age 54 years) with a diagnosis of chronic stable angina pectoris (New York Heart Association Class II-III) were studied. Patients were treated on a double-blind cross-over basis with propranolol 80 mg three times daily or pindolol 5 mg three times daily for 14 days each. During the last 48 h of each treatment period ambulatory electrocardiography was performed. 2. Propranolol resulted in a significantly lower mean hourly, mean 24 h and minimum heart rate. Likewise propranolol caused a lower mean daytime and nocturnal heart rate. There was no significant difference in the frequency of angina between the treatments. The number of episodes of ST segment depression was not significantly different between the two drugs, although there was a trend in favour of propranolol. 3. Both the mean 24 h ST level and the maximum ST segment depression were lower during treatment with pindolol. Propranolol was associated with a total of 117 nocturnal pauses or episodes of asystole ranging in length from 1.5 to 2.8 s. During treatment with pindolol only one such period occurred. The number of premature ventricular contractions occurring during treatment with pindolol (1316 beats) was less than on propranolol (2010) and the mean hourly frequency of premature ventricular contractions was significantly lower during pindolol administration. 4. Pindolol is not significantly different from propranolol in the control of symptomatic and asymptomatic myocardial ischaemia and is associated with fewer premature ventricular contractions. However, there is no advantage in using pindolol in chronic stable angina.

Adult↗
PubMed1987

Beta-adrenoceptor blockade and plasma lipoproteins. Comparison of the effects of propranolol and pindolol on plasma lipoproteins including high-density lipoprotein subfractions.

Beta-Adrenoceptor blocker therapy is known to cause disturbances of the lipoprotein profile. The long-term effects of beta-adrenoceptor blockers and the influence of intrinsic sympathomimetic activity (ISA) has not been clearly defined. We measured serum lipoproteins during chronic beta-adrenoceptor blockade in patients with stable angina pectoris treated with propranolol (without ISA) (n = 21) or pindolol (with ISA) (n = 19). No significant changes occurred in the lipoprotein profile of the patients taking pindolol. In those taking propranolol, very low density lipoprotein (VLDL) increased at 52 weeks (P less than 0.05) and total high density lipoprotein (HDL) decreased at 26 weeks (P less than 0.01) and at 52 weeks (P less than 0.05). However, HDL2 rose significantly at 52 weeks (P less than 0.05). There was a corresponding increase in HDL2/HDL3 ratio. We conclude that pindolol is less likely to exert a harmful effect on plasma lipoproteins than beta-adrenoceptor blockers without ISA.

Adult↗
PubMed1987

How useful are the cold pressor test and sustained isometric handgrip exercise with radionuclide ventriculography in the evaluation of patients with coronary artery disease?

The feasibility of using the cold pressor test and the sustained isometric handgrip test as alternatives to dynamic exercise for stressing the heart was investigated. Serial changes in heart rate, blood pressure, and left ventricular performance induced by these tests were studied by radionuclide ventriculography in patients with coronary artery disease and in normal volunteers. Both tests significantly increased heart rate and blood pressure. The reproducibility of serial evaluation of ejection fraction response to cold pressor and isometric handgrip stresses was satisfactory but the sensitivity for detecting coronary artery disease was not. Both stress tests are valuable interventions for the serial evaluation of left ventricular function by radionuclide ventriculography, but they should not be used to detect coronary artery disease.

Adult↗
PubMed1986

The effect of sotalol on plasma lipoproteins and apolipoproteins.

Plasma lipoproteins were estimated in ten hypertensive subjects (mean age 51 +/- 11.2 yr), before, 6 wk and 6 mth following treatment with Sotalol 320 mg/day. Heart rate fell sequentially throughout the study (p less than 0.01) and although there was a sequential fall in mean blood pressure this did not reach statistical significance. There was a significant increase in plasma triglyceride concentration from a basal value of 1.87 +/- 1.064 to 2.50 +/- 0.877 mmol/l (p less than 0.005) at 6 mth. No significant change was found in very low density, low density and high density lipoprotein cholesterol or apolipoprotein concentrations (Apo A-I, Apo A-II, Apo B). We conclude that Sotalol exerts a similar influence on plasma lipoproteins as other non-cardioselective beta-adrenoceptor blockers without intrinsic sympathomimetic activity and its use does not constitute an increased risk of developing atherosclerosis, when compared with other beta-blockers.

Adult↗