Geometric determinants of electrocardiographic left ventricular hypertrophy

Experimental studies have suggested that electrocardiographic recognition of left ventricular hypertrophy depends on geometric relationships involving wall thickness and chamber size. To determine the clinical significance of these observations, we studied the effects of echocardiographic LV mass (LVM), posterior wall thickness (PWT), interventricular septal thickness (IVST) and internal dimension (LVID) on ECG voltage in 360 patients. Standard voltage and nonvoltage manifestations of LVH correlated modestly with LVM (r = 0.33-0.44, p less than 0.001). Sokolow-Lyon precordial voltage (SLV) (SV1 + RV5 or V6) correlated moderately with LVM (r = 0.41, p less than 0.001), but correlated less well with IVST (r = 0.26), PWT (r = 0.24) or LVID (r = 0.22). Stepwise regression revealed that there was no relation, independent of LVM, between SLV and IVST (r = 0.03), PWT (r = 0.03) or LVID (r = 0.01). The 90 patients with increased LVM (greater than 215 g) but without LVH by SLV (false negatives) were compared with the 48 identified by SLV (true positives). False negatives differed from true positives in LVM (298 +/- 72 vs 339 +/- 98 g, p less than 0.01), age (55 +/- 18 vs 44 +/- 19 years, p less than 0.001), weight (70 +/- 16 vs 63 +/- 14 kg, p less than 0.02), and distance from skin to the interventricular septum (42 +/- 10 vs 38 +/- 8 mm, p less than 0.02). Thus, for a given LVM, ECG voltage criteria of LVH are independent of LV chamber dilatation or other geometric variables, but depend on age, weight and LV depth in the chest, suggesting that stratification of subjects by clinical variables has promise for improved electrocardiographic recognition of LVH.     

Prognostic implications of left ventricular hypertrophy

BACKGROUND: To date there has been no comprehensive review of the association between left ventricular hypertrophy (LVH) at baseline and subsequent adverse clinical events. METHODS: A total of 20 studies (with 48,545 participants) published between January 1960 and January 2000, identified through MEDLINE and other sources, related baseline electrocardiographic (ECG) or echocardiographic data on LVH to subsequent cardiovascular morbidity and all-cause mortality. RESULTS: The prevalence of baseline LVH was higher in echocardiographic studies than in ECG studies (16%-74% vs 1%-44%, respectively). The adjusted risk of future cardiovascular morbidity associated with baseline LVH ranged from 1.5 to 3.5, with a weighted mean risk ratio of 2.3 for all studies combined. The adjusted risk of all-cause mortality associated with baseline LVH ranged from 1.5 to 8.0, with a weighted mean risk ratio of 2.5 for all studies combined. There was a trend toward a worse prognosis among women with baseline LVH compared with men. These findings persisted in the various population and ethnic groups studied. CONCLUSION: With the exception of one study in dialysis patients, LVH consistently predicted high risk, independently of examined covariates, with no clear difference in relation to race, presence or absence of hypertension or coronary disease, or between clinical and epidemiologic samples. These results clarify the strong relation between LVH and adverse outcome and emphasize the clinical importance of its detection.     

Complete left branch block and electrocardiographic diagnosis of left ventricular hypertrophy

The electrocardiogrammes of 71 patients (39 men and 32 women) with transient or intermittent complete left bundle branch block (LBBB) were studied. Two tracings, one with and the other without LBBB were analysed in each case. The interval between the two recordings was less than 90 days in all cases (average 10 days). The diagnosis of left ventricular hypertrophy (LVH) was established from the ECG without LBBB. The sensitivity and specificity of the classical criteria or indices of LVA and of different associations of indices of LVH were assessed on the ECGs with LBBB. The best criteria of LVH in the presence of LBBB were the SV2 + RV6 greater than or equal to 32 mm (sensitivity 80%; specificity 81%), Sokolow's index greater than or equal to 33 mm (sensitivity 78%, specificity 81%); followed by SV1 greater than or equal to 23 mm (sensitivity 73%, specificity 86%), SV1 + SV2 + RV6 + RV7 greater than or equal to 65 mm (sensitivity 88%, specificity 63%), SV1 + SV2 greater than or equal to 54 mm (sensitivity 73%, specificity 74%). These six parameters allow correct diagnosis of LVH in 81%, 79%, 78%, 79% and 73% of cases, respectively. The SV1 + SV2 + RV5 + RV7 and the SV1 + SV2 + RV6 + RV7 greater than or equal to 65 mm indices are the most stable (same sensitivity and specificity for several consecutive threshold values, i.e. 62 to 67 mm and 64 to 66 mm respectively); the results obtained with these two indices are therefore more likely to be reproducible than those of the other indices as they seem less dependent on the sampling. The indices of LVH based on the QRS amplitude in the precordial leads remain valid in the presence of LBBB and are sufficiently reliable for the diagnosis of LVH to be clinically useful.     

Validity of electrocardiographic indices of left ventricular hypertrophy in athletes

The Authors have evaluated the reliability of the most important electrocardiographic criteria for left ventricular hypertrophy in a group of 95 athletes. An ECG and a M- and B-mode echocardiogram have been performed in each subject; the criteria by Sokolow and Lyon, by Cornell, by Gubner, by Romhilt and Estes and by Casale have been employed to evaluate left ventricular hypertrophy. Left ventricular mass has been evaluated by the echocardiogram according to Devereux and coll. The electrocardiographic method by Casale and coll., proposed only for a few years, is based on the valuation of R wave and on the study of ventricular repolarization depending on sex and age. By this method, still now not much used in the study of athletes, a good correlation with the echocardiographic data was expected, in relation to the young age of the population. The athletes have been divided into three groups, practising aerobic sports, aerobic-anaerobic sports and power sports, according to the physiologic classification of the sports activities of Dal Monte. Using the chi-squared test, for the whole population and separately for the three groups, no significant statistical correlation has been observed. In conclusion, the results demonstrate that not only the "classic" criteria, but also the most recent ECG criteria of left ventricular hypertrophy are not reliable in evaluating left ventricular hypertrophy in trained athletes, leaving the final assessment of the real state of the cardiac chambers to echocardiography.     

New precordial bipolar electrocardiographic leads for detecting left ventricular hypertrophy

Background

Novel small and wearable electrocardiogram (ECG) devices offer new means of recording cardiac activity in different applications. Our objective was to evaluate the performance of closely separated (6 cm) bipolar leads in differentiating subjects with left ventricular hypertrophy (LVH) from healthy subjects.

Methods

The material contained body surface ECG of 236 healthy and 116 LVH subjects. A total of 36 vertical, 30 horizontal, and 66 diagonal bipolar leads located on the anterior thorax were analyzed. The QRS amplitudes were calculated, and the leads' overall diagnostic performance was assessed by receiver operating characteristic (ROC) analysis.

Results

The best overall diagnostic performances were obtained from 2 areas: one near the precordial electrodes of standard leads V₁ to V₃ and the other on lower anterior thorax. Vertical and diagonal bipolar leads located at lower anterior thorax provided the highest ROC areas (≥0.79). These bipolar leads also provided similar sensitivities than the traditional Sokolow-Lyon method.

Conclusion

The new short distance vertical and diagonal bipolar leads are efficient in discriminating subjects with LVH from healthy subjects based on QRS amplitude.     

Mild renal dysfunction is associated with electrocardiographic left ventricular hypertrophy

BACKGROUND: Both renal dysfunction and left ventricular hypertrophy (LVH) are signs of end-organ damage, risk markers of cardiovascular (CV) disease and chronic heart failure. In selected populations such as those with diabetes or hypertension, renal dysfunction was found to be related to LVH. We studied the relation between renal dysfunction and LVH in a cross-sectional study in 8592 inhabitants from Groningen, The Netherlands. METHODS: Standard 12-lead electrocardiograms were recorded, and LVH was classified using the Cornell voltage duration product. Renal dysfunction was defined as creatinine clearance <60 mL/min/1.73 m(2) or microalbuminuria (30 to 300 mg/24 h). RESULTS: Electrocardiographic signs of LVH were present in 396 of subjects (5.3%). Subjects with LVH were older and had a more extensive CV risk profile. We found that LVH was more prevalent in subjects with renal dysfunction than in those without (8% v 4%, P < .001). Multivariate regression analysis demonstrated that renal dysfunction was independently related to a 1.47-fold increased risk of the presence of LVH (95% CI = 1.15 to 1.88, P = .009). In addition, both creatinine clearance (OR = 1.56, 95% CI = 1.07 to 2.2, P = .044) and microalbuminuria (OR = 1.37, 95% CI = 1.04 to 1.80, P = .024) were independently associated with the presence of LVH. CONCLUSION: Subjects with mild renal dysfunction have a substantially higher risk of LVH on electrocardiography than those without renal dysfunction.     

Association between electrocardiographic left ventricular hypertrophy with strain pattern and left ventricular structure and function

BACKGROUND AND PURPOSE: Electrocardiographic left ventricular hypertrophy (LVH) with strain pattern has been documented as a marker for LVH. Its presence on the ECG of hypertensive patients is associated with poor prognosis. The study was carried out to assess the association of the electrocardiographic strain with left ventricular mass (LVM) and function in hypertensive Nigerians. MATERIAL AND METHODS: ECG as well as echocardiograms were performed in 64 hypertensive patients with ECG-LVH and strain pattern, 65 patients with ECG-LVH by Sokolow-Lyon (SL) voltage criteria and 62 normal controls. RESULTS: The study showed that electrocardiographic left ventricular (LV) strain pattern is associated with dilated left atrium, larger LV internal dimensions and greater absolute and indexed LVM in hypertensive Nigerians compared with ECG-LVH by SL voltage criteria alone or normal controls. CONCLUSION: The findings of this study support the fact that the ECG strain pattern is associated with increased LVM and an increased risk of developing abnormal LV geometry.     

Regression of electrocardiographic left ventricular hypertrophy following treatment of primary hyperaldosteronism

The electrocardiograms (ECGs) of a series of 34 patients with primary hyperaldosteronism (PHA), 17 treated surgically (group I) nine treated medically (group II) and eight treated with/by both surgery and drug therapy (group III) were analysed to determine whether the treatment of PHA resulted in an improvement in the ECG changes of left ventricular hypertrophy (LVH) and also whether there was a difference in this improvement between medically and surgically treated patients. There was a significant reduction of blood pressure in the group as a whole (186/111 to 141/95 mmHg, P less than 0.001) and within each of the treatment groups (group I 183/108 to 137/98 mmHg, group II 188/112 to 147/93 mmHg, group III 193/115 to 144/92 mmHg). This reduction within each group was of a similar magnitude. There were reductions in both precordial voltages (SV1 + RV5) from 3.68 mV to 2.79 mV (P less than 0.01) and in the number of patients with ECG LVH from 15 to 8 (P less than 0.05). Again the reductions were of similar magnitude in each of the groups: group I 3.78 to 2.77 mV, group II 3.78 to 2.84 mV, group III 3.39 to 2.77 mV. Thus the improvement in blood pressure achieved by the treatment of PHA is accompanied by a reduction in precordial voltages and the number of patients with ECG-LVH. This improvement is independent of the type of treatment used.     

左室肥大心电图诊断重订新标准的探讨

为提高左室肥大心电图诊断的敏感性和准确率,采用超声法对照研究340例16项常用传统心电图左室肥大标准的诊断价值,发现多数单项标准敏感性和准确性不甚理想.提出“新综合记分法”(∑QRS≥175mm、Rv_6>Rv_5、PTFV_1≤-0.04mm·s、QRS≥0.16s各记3分,ST-T改变、电轴左偏 29°——30°各记2分,总记分≥5判为左室肥大),诊断的敏感性和准确性可分别提高至66%(P<0.05)和81%(P<0.01).     

Echocardiographic left ventricular geometry in hypertensive patients with electrocardiographic left ventricular hypertrophy: The LIFE Study

Aim: To assess the prevalence of echocardiographic left ventricular hypertrophy (LVH) and concentric remodeling in hypertensive patients with electrocardiographic (ECG)-LVH and to estimate the costeffectiveness of echocardiography and ECG for detection of LVH.Design: Echocardiographic LV measurements and the prevalence of abnormal LV geometric patterns were compared between 964 hypertensive patients with ECG-LVH (Cornell voltage-duration product > 2440 and/or SV₁