Healthy hearts--a community-based primary prevention programme to reduce coronary heart disease.

BACKGROUND: The ten year probability of cardiovascular events can be calculated, but many people are unaware of their risk and unclear how to reduce it. The aim of this study was to assess whether a community based intervention, for men and women aged between 45 and 64 years without pre-existing coronary heart disease, would reduce their Framingham scores when reassessed one year later. METHODS: Individuals in the relevant age group from a defined geographical area were sent an invitation to attend for an assessment of their cardiovascular risk. Individuals with pre-existing cardiovascular disease or terminal illness were excluded. The invitation was in the form of a "Many Happy Returns" card with a number of self-screening questions including the question, "If you put the enclosed string around your waist, is it too short?" The card contained a red 80 cm piece of string in the case of women, or a green 90 cm piece of string in the case of men. At the assessment appointment, Framingham scores were calculated and a printout was given to each individual. Advice was provided for relevant risk factors identified using agreed guidelines. If appropriate, onward referral was also made to a GP, dietician, an exercise referral scheme, or to smoking cessation services, using a set of guidelines. Individuals were sent a second invitation one year later to return for re-assessment. RESULTS AND DISCUSSION: 2031 individuals were asked to self-assess their eligibility to participate, 596 individuals attended for assessment and 313 of these attended for follow-up one year later. The mean reduction in the Framingham risk score, was significantly lower at one year (0.876, 95% CI 0.211 to 1.541, p = 0.01). The mean 10-year risk of CHD at baseline was 13.14% (SD 9.18) and had fallen at follow-up to 12.34% (SD 8.71), a mean reduction of 6.7% of the initial 10-year Framingham risk. If sustained, the estimated NNT to prevent each year of CHD would be 1141 (95% CI 4739 to 649) individual appointments. CONCLUSION: This community intervention for primary prevention of CHD reduces Framingham risk scores at one year in those who engage with the programme.

Heart rate turbulence after atrial and ventricular premature beats: relation to left ventricular function and coupling intervals.

UNLABELLED: Heart rate turbulence (HRT) represents a biphasic chronotropic response of the sinus node to a single ventricular premature beat (VPB). OBJECTIVES: To determine whether HRT is present after an atrial premature beat (APB) and to investigate the effects of paced VPB and APB coupling intervals on HRT quantifiers in patients with and without left ventricular dysfunction. METHODS: A total of 37 subjects (54 +/- 16 years, 32 men) referred for electrophysiologic evaluation for ventricular tachycardia underwent a stimulation protocol consisting of 3 series of single atrial and ventricular extrastimuli with coupling intervals decremented from 750 to 400 ms at a 50 ms-step. Turbulence onset (TO) and turbulence slope (TS) after an APB and a VPB were calculated separately using a dedicated computer algorithm. RESULTS: After an APB, TS was significantly attenuated (3.95 +/- 0.99 vs 8.32 +/- 1.9 ms/RR, P < 0.008) and TO was positive (1.37 +/- 0.35% vs -2.03 +/- 0.42%, P < 0.001) compared with those after a VPB. There was a strong correlation between TS (r = 0.71, P = 0.0002) but not between TO (r = 0.07, P = 0.074) after an APB and a VPB. In subjects with normal ejection fraction, the prematurity of ventricular coupling intervals was strongly related to TO (r = 0.68) and TS (r = -0.61), P < 0.0001 for both. These effects were less pronounced in patients with left ventricular dysfunction (TO: r = 0.25, P < 0.01; TS: r = -0.07, P = ns). No correlation was found between the APB coupling interval and TS or TO in both groups. CONCLUSIONS: An APB induces HRT but the response is substantially attenuated and is not influenced by the APB coupling interval. In contrast to a VPB, TO is positive after an APB. Lack of correlation between HRT after a VPB and the VBP coupling interval indicates blunted baroreflex response in patients with left ventricular dysfunction.

QT-RR relationship in healthy subjects exhibits substantial intersubject variability and high intrasubject stability.

Recently, it was demonstrated that the QT-RR relationship pattern varies significantly among healthy individuals. We compared the intra- and interindividual variations of the QT-RR relationship. Twenty-four-hour 12-lead digital electrocardiograms (ECGs; SEER MC, GE Marquette; 10-s ECG recorded every 30 s) were obtained at baseline and after 24 h, 1 wk, and 1 mo in 75 healthy subjects (42 women, 33 men, age 27.9 +/- 9.6 vs. 26.8 +/- 7.5 yr, P = not significant). QT interval was measured automatically in each ECG by six different algorithms, and the mean of the six measurements was analyzed. In each recording of each individual, QT-RR relationship was assessed by 10 different regression models including linear (QT = beta + alpha x RR) and parabolic (QT = beta x RR(alpha)) models. Standard deviations (SDs) of regression parameters alpha and beta of consecutive recordings of each individual were compared with SD of the individual means. Intrasubject stability and interindividual variability were further tested by ANOVA. With all models, intraindividual SDs of the regression parameters were highly significantly smaller than SD of individual means (P < 10(-5)-10(-9)). The intrasubject stability was further confirmed by ANOVA (P < 10(-19)-10(-30)). The QT-RR relationship exhibits substantial intersubject variability as well as a high intrasubject stability. This has practical implications for a precise estimation of the heart rate-corrected QT interval in which optimized subject-specific rate correction formulas should be used.