Baseline rest electrocardiographic abnormalities,antihypertensive treatment,and mortality in the Multiple Risk Factor Intervention Trial

The overall results of the Multiple Risk Factor Intervention Trial (MRFIT) showed a nonsignificant 7% lower coronary artery disease (CAD) mortality rate in the special-intervention (SI) as compared to the usual-care (UC) group. The initial results also suggested that the SI program was more effective than UC in the community in reducing the CAD mortality rate in nonhypertensive persons than in hypertensive persons, and that the SI program used was more effective in reducing CAD deaths among men without than men with electrocardiographic (ECG) abnormalities at rest. Furthermore, an unfavorable mortality trend in hypertensive SI men with ECG abnormalities at rest compared with UC men was noted (adjusted relative risk of 1.67). Further analyses in baseline-defined subgroups indicated that (1) the most common ECG abnormalities at rest were high R waves and ST-T changes, (2) the CAD mortality differential (SI/UC) was similar in the subgroup with these abnormalities and in the subgroup with other abnormalities at rest, (3) the apparent excess CAD mortality among hypertensive SI men with ECG abnormalities at rest was manifested chiefly as sudden death within 1 hour, and (4) the association between ECG abnormalities at rest and the CAD mortality rate among hypertensive men was independent of the baseline level of blood pressure or of the findings on the exercise electrocardiogram. However, CAD mortality in those with abnormalities on the electrocardiogram both at rest and during exercise was lower in the SI than the UC group.A possible explanation for the difference in outcome in the baseline-defined subgroup was an unexpectedly low UC mortality rate. However, within-group analysis revealed an interaction between ECG abnormalities at rest and diuretic treatment in the SI group, with the risk of CAD death for men prescribed diuretic drugs relative to men not prescribed diuretic drugs estimated as 3.34 among men with baseline ECG abnormalities at rest and as 0.95 among men without such abnormalities. No such effect was found in the UC group, in which men generally were prescribed lower doses of hydrochlorothiazide and chlorthalidone than SI men. However, analyses do not suggest an effect of diuretic dose or of hypokalemia on the CAD mortality rate in treated SI participants. Although subgroup analyses must be interpreted with caution, particularly those that go beyond the randomized clinical trial design by the MRFIT, these findings pose hypotheses for investigation by other researchers in systemic hypertension and may have implications for therapy.     

Diuretics, serum potassium and ventricular arrhythmias in the Multiple Risk Factor Intervention Trial

To examine the relation between diuretic use and ventricular premature complexes (VPCs) in the Multiple Risk Factor Intervention Trial, data derived from the baseline and annual rest electrocardiograms were analyzed for men in the special-intervention (SI) and usual-care (UC) groups. At baseline, age, diuretic use and presence of other rest electrocardiographic abnormalities were significantly associated with the prevalence of VPCs. Among diuretic users at baseline, those with lower serum potassium levels were most likely to have VPCs. Over the follow-up period among nonhypertensive persons the relative risk (SI/UC) for the occurrence of VPCs during follow-up was 0.83, and for hypertensives this relative risk increased linearly from 1.08 to 1.42, with higher levels of diastolic blood pressure at entry (p less than 0.01 for linear trend of relative risk estimates). This was due to an increasing risk among the SI group, and the risk was independent of the presence or absence of rest electrocardiographic abnormalities at baseline. The relative risk estimate, diuretic vs no diuretic, for development of VPCs was approximately 1.2 (p = 0.04) for SI men and 1.1 (p = 0.35) for UC men. The reduction in serum potassium level was greater for those with VPCs, and regression analysis showed that low serum potassium levels were significantly associated with the incidence of VPCs in both study groups. These data confirm and quantify the relation between diuretic drugs and VPCs and suggest that at least 1 mechanism of diuretic-induced VPCs is potassium depletion.     

Hypertension management in the Multiple Risk Factor Intervention Trial (MRFIT). Six-year intervention results for men in special intervention and usual care groups

The Multiple Risk Factor Intervention Trial was a large collaborative primary prevention trial designed to test the effects of lowering cardiovascular risk factors (ie, diastolic blood pressure [DBP], serum cholesterol, and cigarette smoking) on mortality rate from coronary heart disease in 12,866 high-risk men aged 35 to 57 years. Men were randomly assigned to either special intervention (SI) or usual care (UC) groups. Usual care men were referred to their regular source of medical care. Special intervention men were seen frequently and underwent intensive intervention initially followed by maintenance intervention in 22 different clinical centers. Hypertension intervention in SI men primarily consisted of a stepped-care pharmacologic approach designed to lower blood pressure (BP). After six years, 58.2% of SI men and 47.0% of UC men were given antihypertensive medication. In both study groups, mean systolic and diastolic BPs decreased from baseline; after six years, overall DBP was 3.2 mm Hg lower in SI men compared with UC men. In hypertensive men (DBP greater than or equal to 90 mm Hg or those taking antihypertensive medication at baseline), after six years, DBP was 4.4 mm Hg lower in the SI group compared with the UC group. Use of specific antihypertensive agents differed substantially between the two groups. Self-reported complaints while taking antihypertensive drugs were minimal in both groups. Weight loss was associated with BP lowering in both study groups, regardless of treatment status.     

Improved cardiovascular risk stratification by a simple ECG index in hypertension

BACKGROUND: We determined the prognostic value of the Cornell/strain [C/S] index, a simple electrocardiographic (ECG) index for left ventricular hypertrophy (LVH) defined by the presence of either a classic strain pattern or a Cornell voltage (sum of R in aVL + S in V(3)) >2.0 mV in women or 2.4 mV in men, or both. METHODS: In a prospective, cohort study, 2190 initially untreated subjects (age 51 [+/- 12], 47% women) with essential hypertension without prior events were followed for up to 14 years (median, 5 years). RESULTS: Prevalence of LVH at entry was 16.3% by using the C/S index, which yielded 33.6% sensitivity and 91.0% specificity. Other ECG criteria for LVH including Sokolow-Lyon, Romhilt-Estes, Framingham, Cornell, and strain alone, achieved a lower sensitivity and prevalence. Over the subsequent follow-up, 244 patients experienced a first major cardiovascular event. Event rate (x 100 person-years) was 2.01 in those without and 4.44 in those with LVH by the C/S index (P <.001). After adjustment for age, sex, smoking, and other counfounders, the C/S index identified subjects at increased risk of events (relative risk 1.76; 95% confidence interval 1.32-2.33). The C/S index achieved the highest population-attributable risk (16.1%) for cardiovascular events. CONCLUSIONS: A simple ECG index that can be quickly measured from nondigital machines and without algorithms identifies LVH in a consistent proportion (16.3%) of hypertensive subjects. The LVH defined by such technique allows identification of individuals at high risk for cardiovascular events.     

Gender differences in regression of electrocardiographic left ventricular hypertrophy during antihypertensive therapy

Although men and women differ in the magnitude of ECG left ventricular hypertrophy, whether gender differences exist in the degree of regression of ECG left ventricular hypertrophy during antihypertensive therapy is unclear. ECG left ventricular hypertrophy defined using gender-adjusted Cornell product and Sokolow-Lyon voltage criteria was assessed serially in 9193 hypertensive patients treated with losartan- or atenolol-based regimens. Changes in ECG left ventricular hypertrophy were measured from baseline to last in-study visit, and above-average regression of hypertrophy was identified by a >or=236-mm . ms reduction in Cornell product or >or=3.5-mm reduction in Sokolow-Lyon voltage. During mean follow-up of 4.8+/-0.9 years, women had less reduction in Cornell product (-149+/-823 versus -251+/-890 mm . ms) and Sokolow-Lyon voltage (-3.0+/-6.8 versus -4.8+/-7.7 mm) than men (both P<0.001). After adjusting for baseline ECG left ventricular hypertrophy levels, baseline and change in systolic and diastolic pressures, treatment group, age, and other baseline gender differences, women had significantly less reduction in both Cornell product (adjusted means: -137 versus -276 mm . ms; P<0.001) and Sokolow-Lyon voltage (-3.6 versus -4.1 mm; P=0.005) than men and were 32% less likely to have had greater than the median level of regression of Cornell product left ventricular hypertrophy (95% CI: 24% to 39%; P<0.001) and 15% less likely to have had regression of left ventricular hypertrophy by Sokolow-Lyon criteria (95% CI: 5% to 23%; P=0.003). Thus, women have less regression of ECG left ventricular hypertrophy than men in response to antihypertensive therapy, independent of baseline gender differences in the severity of ECG left ventricular hypertrophy and after taking into account treatment effects and blood pressure changes.     

Underserved urban african american men: hypertension trial outcomes and mortality during 5 years

BACKGROUND: African American men with hypertension (HTN) in low socioeconomic urban environments continue to achieve poor rates of HTN control. METHODS: In a 5-year randomized clinical trial with 309 hypertensive urban African American men aged 21 to 54 years, the effectiveness of a more intensive educational/behavioral/pharmacologic intervention provided by a nurse practitioner/community health worker/physician team was compared to less intensive information and referral intervention. Changes in behavioral factors, health care utilization, blood pressure (BP) control, left ventricular hypertrophy (LVH), and renal insufficiency were evaluated. RESULTS: Follow-up rates exceeded 89% of available men. The ranges of mean annual systolic BP/diastolic BP change from the baseline to each year follow-up were -3.7 to -10.1/-4.9 to -12.3 mm Hg for the more intensive group and +3.4 to -3.0/-1.8 to -8.7 mm Hg for the less intensive group. The annual proportion of men with controlled BP (<140/90 mm Hg) ranged from 17% to 44% in the more intensive group and 21% to 36% in the less intensive group. At 5 years the more intensive group had less LVH than the less intensive group and 17% of the men were deceased primarily due to narcotic or alcohol intoxication (36%) and cardiovascular causes (19%). CONCLUSIONS: An appropriate educational/behavioral intervention significantly improved BP control and reduced some sequelae of HTN in a young African American male population. Improvement in risk factors other than HTN was limited and sustained control of HTN was difficult to maintain during 5 years.     

Lowering of blood pressure and predictors of response in patients with left ventricular hypertrophy: the LIFE study. Losartan Intervention For Endpoint

The Losartan Intervention For Endpoint (LIFE) reduction in hypertension study is a double-blind, prospective, parallel-group study comparing the effects of losartan with those of atenolol on the reduction of cardiovascular complications in patients (n = 9,194) with essential hypertension and with electrocardiographically (ECG) documented left ventricular hypertrophy (LVH). Baseline blood pressure was 174.4/97.8 mm Hg (mean), age 66.9 years, body mass index 28.0 kg/m2; 54.1% were women and 12.5% had diabetes mellitus. This population will be treated until at least 1,040 have a primary endpoint. After five scheduled visits and 12 months of follow-up, blood pressure decreased by 23.9/12.8 mm Hg to 150.5/85.1 mm Hg (target < 140/90 mm Hg). The mandatory titration level of < or = 160/95 mm Hg was reached by 72.1% of the patients. At the 12-month visit, 22.7% of all patients were taking blinded study drug alone, 44.3% were taking blinded drug plus hydrochlorothiazide (HCTZ), and 17.7% were taking blinded drugs plus HCTZ and additional drugs. Controlling for all other variables, patients in the US received more medication and had 2.4 times the odds of achieving blood pressure control than patients in the rest of the study (P < .001). Previously untreated patients (n = 2,530) had a larger initial decrease in blood pressure compared with those previously treated. Diabetics (n = 1,148) needed more medication than nondiabetics to gain blood pressure control. Only 13.9% of the patients had discontinued blinded study drug and 1.4% missed the revisit at 12 months. These data demonstrate both the successful lowering of blood pressure during 12 months of follow-up in a large cohort of patients with hypertension and LVH on ECG, but also emphasize the need for two or more drugs to control high blood pressure in most of these patients. Being previously treated and having diabetes were associated with less blood pressure response, whereas living in the US indicated better blood pressure control. It has been possible to keep most of these patients with complicated hypertension taking blinded study drug for 12 months.     

Left ventricular hypertrophy in patients with renal artery stenosis

Left ventricular hypertrophy (LVH) has been shown to be 3 times more prevalent in patients with renal artery stenosis (RAS) compared to essential hypertension, but factors that predict LVH in this population are not known. We identified 66 patients with unilateral renal artery stenosis and an interpretable electrocardiogram (ECG). LVH by either Cornell voltage-duration product or Sokolow-Lyon voltage criteria was present in 18 of the 66 patients (27%). The mean intra-aortic blood pressure was 100 +/- 14 mm Hg in patients with LVH, and 104 +/- 23 mm Hg in those without LVH (P = 0.37). The average stenosis by quantitative computerized angiography was 68 +/- 17% in patients with LVH, and 64 +/- 13% in those without LVH (P = 0.34). The mean translesional pressure gradient was 11 +/- 15 mm Hg in patients with LVH, and 13 +/- 20 mm Hg in those without LVH (P = 0.60). Using linear regression models, there was no correlation between intra-aortic blood pressure, percentage of stenosis, or translesional pressure gradient and either Cornell voltage-duration product or Sokolow-Lyon voltage criteria. In summary, LVH using ECG criteria was present in 27% of patients with unilateral RAS but was not associated with blood pressure at the time of the procedure or severity of renal artery stenosis.     

Left ventricular hypertrophy determined by Sokolow-Lyon criteria: a different predictor in women than in men?

The clinical usefulness of the Sokolow-Lyon voltage criteria in the assessment of electrocardiographic left ventricular hypertrophy (ECG LVH) is addressed. We prospectively studied 3,338 women and 3,330 men referred with hypertension, with an average follow-up of 11.2 years. The voltage amplitude sum SV1+max (RV5 or RV6) was calculated and ECG LVH was defined as a sum >or=3.5 mV. We adjusted survival for age, treatment status before presentation and a previous myocardial infarction or cerebrovascular accident. The risk of stroke, coronary heart disease (CHD) and cardiovascular disease (CVD) mortality increased significantly for each quantitative 0.1 mV increase in baseline electrocardiogram (ECG) voltage, in women within the range of 1.6-3.9% and in men 1.4-3.0%. After further adjustments for race, body mass index, smoking and systolic blood pressure, increasing voltage independently predicted CVD mortality in both men and women. In women, both increasing voltage and the presence of left ventricular hypertrophy (LVH) were predictors of stroke mortality, whereas in men this risk was attenuated. In men, the adjusted association between increasing voltage and CHD mortality tended to be stronger than in women. The use of different thresholds for the two genders made little difference. For stroke and CHD mortality, the population attributable fractions associated with LVH were 15.2 and 5.4% in women and 12.8 and 8.5% in men, respectively. In conclusion, the greater the baseline ECG voltage sum, the greater the associated CVD mortality risk. Women tended to have a high risk of stroke mortality owing to LVH despite adjustments.     

Impaired systolic and diastolic function and ventricular arrhythmia are common in normotensive healthy elderly men with left ventricular hypertrophy

BACKGROUND: The present study was designed to assess the impact of left ventricular hypertrophy (LVH) independent of hypertension on the presence of silent myocardial ischemia and arrhythmia, as well as on systolic and diastolic function in otherwise healthy elderly men. METHODS AND RESULTS: Twenty apparently healthy normotensive subjects with LVH were compared with 18 hypertensive subjects with LVH and with 20 healthy subjects without LVH (controls)--all recruited from a health screening programme of 70-year-old men. All participants were free from known coronary heart disease and were evaluated by means of echocardiography with Doppler, a symptom-limited exercise test and 24 h ambulatory ECG monitoring. The healthy normotensive subjects with LVH showed impaired systolic function (ejection fraction 66 +/- 8 (SD)% versus 72 +/- 8% in controls, P < 0.03) and impaired diastolic function (E/A ratio 0.86 +/- 0.20 versus 1.12 +/- 0.30, P < 0.01) as well as an increased number of premature ventricular complexes in the exercise test and during the 24 h ECG monitoring (P < 0.05), when compared with the healthy group without LVH. The hypertensive subjects with LVH showed impaired diastolic function (P < 0.05) and a more pronounced ST depression in the exercise test (P < 0.05), when compared with the healthy group without LVH. In both of the LVH groups, more than 20% of the subjects evidenced ST-segment depression > or = 1 mm in the exercise test, compared with 5% of the healthy group without LVH. CONCLUSIONS: In elderly men free from hypertension or other known disease, LVH at echocardiography was associated with impaired systolic and diastolic function as well as with ventricular arrhythmia. Thus, even in the absence of hypertension, LVH may be a harmful characteristic in the elderly.     

Exercise electrocardiogram and coronary heart disease mortality in the Multiple Risk Factor Intervention Trial

The Multiple Risk Factor Intervention Trial (MRFIT), a coronary heart disease (CAD) primary prevention trial, examined the effect on the CAD mortality rate of a special intervention (SI) program to reduce blood cholesterol level, diastolic blood pressure and cigarette smoking in 35- to 57-year-old men. Half of the 12,866 participants were randomly assigned to usual care (UC) in the community. During 6 to 8 years of follow-up, the CAD mortality rate was 7% lower in the SI than in the UC group, a nonsignificant difference. An a priori subgroup hypothesis proposed that men with a normal electrocardiographic response to a heart-rate-limited exercise test would experience particular benefit from intervention. An abnormal response, defined as an ST-depression integral measured by computer greater than a pre-determined voltage-time cutpoint, was observed in 12.5% of the men at baseline, and was associated with a 3-fold elevation in risk of CAD death within the UC group. In the subgroup with a normal exercise electrocardiographic response, there was no significant SI-UC difference in the CAD mortality rate (16.0 and 13.8 per 1,000, respectively, for SI and UC men). In contrast, there was a 57% lower rate among men in the SI group with an abnormal test result compared with men in the UC group (22.2 vs 51.8 per 1,000). The relative risks (SI/UC) in these 2 strata were significantly different (p = 0.002). These findings suggest that men with elevated risk factors who have an abnormal exercise test response may benefit substantially from risk factor reduction.     

Validity of the ECG diagnosis of left ventricular hypertrophy in normotensive and moderately hypertensive men when using the echocardiographic assessment of left ventricular mass index as reference.

The diagnostic validity of ECG criteria for left ventricular hypertrophy (LVH) was assessed in 100 men aged 22-64 (mean 47) years with moderate hypertension (Group 1) and 95 age-matched normotensive men (Group 2) using echocardiographic recordings of LV mass index (MI) as reference. A diagnosis of LVH was made in subjects with LVMI greater than or equal to 125 g/m2. Mean LVMI was 126 +/- 34 g/m2 in Group 1 vs. 100 +/- g/m2 in Group 2 (P less than 0.001), and the prevalence of LVH was 48% and 11% respectively (P less than 0.001). The mean ECG voltage according to Sokolow-Lyon (S-L) was 28 +/- 8 mm in Group 1 and 27 +/- 7 mm in Group 2 (NS); with 19% having LVH in Group 1 and 14% in Group 2 (NS). Using the Cornell criterion Group 1 had on average 15 +/- 6 mm vs. 12 +/- 5 mm in Group 2 (P less than 0.001), but only two Group 1 patients had LVH. In Group 2 a significant negative correlation between age and S-L voltage was found (r = 0.33, P less than 0.001). LVMI was not correlated with any of the two voltage criteria using linear regression analysis whereas multiple regression analysis revealed a weak, but significant correlation between LVMI and S-L voltage in Group 1 (t = 2.06, P = 0.04). No subject had LV strain pattern or LVH according to the Romhilt Estes point score system. In the assessment of possible LVH in normal or moderately hypertensive men less than 65-70 years of age, ECG has limited value.     

Electrocardiographic and echocardiographic detection of myocardial infarction in patients with left-ventricular hypertrophy. The LIFE Study

BACKGROUND: Left-ventricular hypertrophy (LVH) is a recognized risk factor for myocardial infarction (MI). However, detection of MI by standard electrocardiographic (ECG) criteria may be hampered in patients with LVH. In this setting of hypertensive LVH, the accuracy of two-dimensional (2D) echocardiography in detecting incident MI is unknown. Thus, we compared the accuracy of 2D echocardiography with Minnesota-code ECG criteria in detecting incident MI, adjudicated during serial evaluation in patients with hypertension and LVH. METHODS: In the ECG substudy of the Losartan Intervention for Endpoint Reduction in Hypertension (LIFE) Study, complete baseline wall-motion (WM) evaluation was obtained in 904 hypertensive patients with ECG LVH who did not have a left-bundle branch block. Electrocardiography and echocardiograms obtained at annual follow-up visits were evaluated for ECG Q-waves by Minnesota codes and WM abnormalities, respectively (mean follow-up, 4.8+/-0.9 SD years). Occurrence of incident clinical MI during follow-up was adjudicated by an expert end-point committee. RESULTS: In two logistic models adjusting for confounders, incident MI was independently associated with either incident Q-waves by the Minnesota code (odds ratio [OR], 6.1; 95% confidence interval [CI], 2.4-15.3) or incident and worsened WM abnormalities (OR, 11.9; 95% CI, 4.5-32.0), and the association was stronger for WM abnormalities than for Q-waves (P < .0001). Detection of incident MI by ECG or 2D echocardiography was obtained with sensitivities of 29% and 68% and specificities of 95% and 84%, respectively. CONCLUSIONS: Wall-motion abnormalities on serial 2D ECGs recognize incident MI better than do Minnesota-code ECG criteria during follow-up of patients with hypertension and LVH.     

Prognostic value of serial electrocardiographic voltage and repolarization changes in essential hypertension: the HEART Survey study

BACKGROUND: The interpretation of serial electrocardiographic (ECG) changes in hypertensive subjects is uncertain. We tested the hypothesis that serial changes in repolarization and voltage are independent determinants of outcome. METHODS: The Hypertrophy at ECG And its Regression during Treatment (HEART) Survey was a prospective observational study performed at 61 centers. We studied 711 subjects with hypertension and ECG left-ventricular hypertrophy (LVH) at entry. Tracings from 496 subjects at entry and one or more visits during follow-up were available for central reading. RESULTS: The prevalence of ECG LVH progressively decreased by 49.6% at 3 years. The crude rate of a prespecified primary composite end point of cardiovascular events was 4.17 per 100 subjects per year (95% confidence interval [CI], 3.27 to 5.33). We used Cox regression models of ECG LVH indexes as time-varying covariates at baseline and at follow-up. Time-varying LVH, defined as an absence of ST-T alterations ("strain"), was associated with a lower event rate hazard ratio (HR), 0.47; 95% CI, 0.28 to 0.78; P = .0035), whereas the LVH changes defined in terms of ECG voltages did not achieve significance (HR, 0.91; 95% CI, 0.74 to 1.13; P = .39). The crude event rate in subjects with versus without in-treatment ST-T alterations on the last available ECG before the event or before censoring was 8.38 versus 3.17 per 100 subjects per year (P < .0001). CONCLUSIONS: In this study of subjects with hypertension and ECG LVH at entry, serial changes in repolarization significantly predicted the prognosis, independent of voltage change (which was not significantly predictive in this study). The persistence or new development of ST-T alterations identifies subjects at very high risk of cardiovascular events.     

Usefulness of echocardiographic left ventricular hypertrophy and silent ischemia in predicting new cardiac events in elderly patients with systemic hypertension or coronary artery disease

The authors performed a prospective study to correlate echocardiographic left ventricular hypertrophy (LVH) and silent ischemia (SI) detected by twenty-four-hour ambulatory electrocardiographic monitoring with new cardiac events in 355 patients, mean age eighty-two +/- eight years, with systemic hypertension or coronary artery disease (CAD). Cardiac events included myocardial infarction, primary ventricular fibrillation, or sudden cardiac death. Mean follow-up was thirty-one +/- seven months (range twelve to forty). Cardiac events occurred in 28 of 147 patients (19%) without LVH or SI (A), in 56 of 113 patients (50%) with LVH and no SI (B), in 16 of 29 patients (55%) with SI and no LVH (C), and in 52 of 66 patients (79%) with LVH and SI (D). Significant p values were p less than 0.001 comparing D with A, D with B, C with A, and B with A; and p less than 0.02 comparing D with C. These data indicate that echocardiographic LVH and SI detected by ambulatory electrocardiographic monitoring are independent risk factors for new cardiac events in elderly patients with systemic hypertension or CAD.     

Clinical importance of coronary perfusion pressure in the hypertensive patient with left ventricular hypertrophy.

In patients with severe left ventricular hypertrophy (LVH), but no significant coronary artery disease (CAD), acute lowering of diastolic blood pressure (DBP) to less than 85 mm Hg is reported to result in a 26% fall in coronary blood flow and an increase in myocardial oxygen demand; S-T segment and T-wave changes in the ECG are observed when DBP is acutely lowered to the 70s in these patients. In the presence of good resting left ventricular function, acute lowering of DBP to the 60s in well-controlled hypertensives on a beta-blocker, with either CAD or LVH, results in a mean increase of about 20% in ventricular ejection fraction. By contrast, patients with a combination of CAD and LVH experience a mean 6% fall in ejection fraction implying poor left ventricular functional reserve. In low risk populations, which exclude patients with severe ischaemia, diabetics and smokers, the lower the DBP the fewer the number of myocardial infarctions. However, in heterogeneous hypertensive populations which include high risk patients, such as ischaemics and diabetics (e.g. the MRFIT population), there is a strong U- or J-curve relationship between DBP and CAD deaths. Meta-analysis of high quality studies involving heterogeneous populations has shown that the U- or J-point is at 84 mm Hg and probably relates to high risk patients with ischaemia and/or LVH. Recent data from the Framingham group indicate that the patients most at risk are those with a combination of CAD and LVH: these patients showed a marked U-shaped curve with the U- or J-point at about 85-89 mm Hg DBP.(ABSTRACT TRUNCATED AT 250 WORDS)     

肥厚型心肌病体表心电图特征

目的 探讨肥厚型心肌病（HCM）患者体表心电图（ECG）特征。 方法 选取2015年5月~2017年4月期间住院治疗的HCM患者60例，同时选取本院同期查体的正常人60例，作为对照组，要求两组人员性别、年龄、体质量指数匹配。分析ECG各导联QRS波时限和R波、S波振幅，异常q波情况，QTC时限，R/S比值， ST段下移与抬高，T波低平、倒置，P波时限等指标。 结果 ①HCM组的V2、V3导联QRS波时限；Ⅱ、V4导联异常Q波比例；QTC时限；P波时限；左心室肥厚ECG诊断公式SV1+RV5/V6及（SV3+RaVL）×QRS波时限均显著高于正常对照组。②HCM组的I、aVR、aVL、aVF导联QRS波时限；aVR导联Q波所占比例； I、Ⅱ、Ⅲ、aVL、aVF、V3、V4、V5、V6导联QRS波主波与T波方向一致性； V4、V5、V6导联R/S比值均显著低于正常对照组。 结论 ECG诊断HCM首先要满足左心室肥厚的诊断标准，再结合上述ECG导联的特异性参数进行综合判断。     

Left ventricular hypertrophy in men with normal blood pressure: relation to exaggerated blood pressure response to exercise

OBJECTIVE: To determine whether normal, nonhypertensive subjects who have unusually large increases of systolic blood pressure with exercise have left ventricular hypertrophy (LVH). DESIGN: Case-comparison using echocardiography as a criterion standard for measurement of left ventricular mass and the diagnosis of LVH. SETTING: Population-based health fitness screening program and referral Veterans Affairs Hospital. SUBJECTS: Thirty-nine men (average age, 44.6 +/- 8.5 years; range, 34 to 71 years) were studied, including 25 participants in a health fitness screening program and an additional 14 normal men with atypical chest pain. Twenty-two subjects with a systolic blood pressure during peak exercise of 210 mm Hg or greater were compared with 17 others with systolic pressure less than 210 mm Hg during exercise. MEASUREMENTS AND MAIN RESULTS: Left ventricular hypertrophy (left ventricular mass index greater than 134 g/m2) was found in 14 of 22 men with a systolic blood pressure of 210 mm Hg or greater (present in 6.3% of normotensive healthy male volunteers in a health screening program) but in only 1 person with a lower exercise blood pressure. Left ventricular mass index was linearly correlated (r = 0.65, n = 39, P less than 0.001) with maximum exercise blood pressure. Whereas LVH was mild in about 50%, substantial LVH was present in the others. The presence of LVH was not related to superior physical conditioning and was accompanied by increased left atrial size suggesting impaired left ventricular filling. CONCLUSIONS: Even in the absence of hypertension, exaggerated blood pressure responses during exercise testing suggest a probability of 0.64 (95% CI, 0.41 to 0.83) of LVH, a finding associated with the cardiac "end-organ" manifestations of hypertension.     

Glucose effectiveness is strongly related to left ventricular mass in subjects with stage I hypertension or high-normal blood pressure

BACKGROUND: Evidence suggests that "glucose effectiveness," (SG) or the effect of glucose per se to enhance net glucose disposal, may be at least as important as the insulin sensitivity index (SI) in the assessment of glucose tolerance. Our objective was to study the relationship of SG and SI parameters to left ventricular mass in a group of untreated, nondiabetic, and nonobese subjects recently diagnosed with stage I or high-normal blood pressure (BP). METHODS: In this sample of subjects, among whom the expected prevalence of insulin resistance is low, we assessed SG and SI parameters using the intravenous glucose tolerance test and minimal model analysis. We also measured left ventricular mass (LVM) index and diastolic function by echocardiography. RESULTS: We observed a strong relationship between SG and LVM index (r = -0.61, P <.0001). Patients with left ventricular hypertrophy (LVH) had lower SG than those without LVH (0.1114 +/- 0.04 v 0.2088 +/- 0.08 x 10(-1). min(-1), P <.001). In contrast, patients below the lowest quartile of the SG parameter distribution had higher LVM index (126.4 +/- 23.1 v 94.8 +/- 22.3 g/m(2), P <.001) and also had higher prevalence of LVH than the other patients (P <.0001). The SI related only to diastolic dysfunction, suggesting that SG may be an earlier marker of LVH than SI in hypertension. CONCLUSION: In this sample of nonobese and glucose-tolerant subjects with an early stage of hypertension, SG but not SI was related to LVM.     

Electrocardiographic patterns of patients with echocardiographically determined biventricular hypertrophy.

The numerous criteria proposed for the electrocardiographic (ECG) diagnosis of biventricular hypertrophy (BVH) suffer from inadequate correlative data. We used two-dimensional (2D) echocardiography to identify BVH and analyzed the ECG patterns in these patients. The study group had 69 such patients with BVH and the control group had 22 patients with isolated left ventricular hypertrophy (LVH) demonstrated by 2D echocardiography. The electrocardiograms were analyzed for the presence of established criteria used in the diagnosis of LVH and right ventricular hypertrophy (RVH). Of the 69 patients in the study group, 17 (25%) had ECG findings of BVH, 25 (36%) had LVH, and 14 (20%) had RVH. An S wave in V5/V6 of >7 mm was most the frequent finding in the 17 patients with BVH on the electrocardiogram. The sensitivity of ECG criteria for BVH was 24.6%, specificity was 86.4%, and positive predictive value was 85%. This study reemphasizes the difficulty of ECG diagnosis of BVH. The electrocardiogram has a low sensitivity but satisfactory specificity and positive predictive accuracy for BVH.