Limitations of Electrocardiography for Detecting Left Ventricular Hypertrophy or Concentric Remodeling in Athletes

Limited Relationship Between Echocardiographic Measures and Electrocardiographic Markers of Left Ventricular Size in Healthy Children

Pediatric ECG standards have been defined without echocardiographic confirmation of normal anatomy. The Pediatric Heart Network Normal Echocardiogram Z-score Project provides a racially diverse group of healthy children with normal echocardiograms. We hypothesized that ECG and echocardiographic measures of left ventricular (LV) dimensions are sufficiently correlated in healthy children to imply a clinically meaningful relationship. This was a secondary analysis of a previously described cohort including 2170 digital ECGs. The relationship between 6 ECG measures associated with LV size were analyzed with LV Mass (LVMass-z) and left ventricular end-diastolic volume (LVEDV-z) along with 11 additional parameters. Pearson or Spearman correlations were calculated for the 78 ECG-echocardiographic pairs with regression analyses assessing the variance in ECG measures explained by variation in LV dimensions and demographic variables. ECG/echocardiographic measurement correlations were significant and concordant in 41/78 (53%), though many were significant and discordant (13/78). Of the 6 ECG parameters, 5 correlated in the clinically predicted direction for LV Mass-z and LVEDV-z. Even when statistically significant, correlations were weak (0.05-0.24). R2 was higher for demographic variables than for echocardiographic measures or body surface area in all pairs, but remained weak (R2 ≤ 0.17). In a large cohort of healthy children, there was a positive association between echocardiographic measures of LV size and ECG measures of LVH. These correlations were weak and dependent on factors other than echocardiographic or patient derived variables. Thus, our data support deemphasizing the use of solitary, traditional measurement-based ECG markers traditionally thought to be characteristic of LVH as standalone indications for further cardiac evaluation of LVH in children and adolescents.

Electrocardiographic manifestations in female team handball players: analyzing ECG changes in athletes

Introduction

Long-term intense training leads to structural, functional, and electrical remodeling of the heart. How different sports affect the heart has not been fully investigated, particularly for female athletes. The aim of the present study was to investigate the morphology of 12-lead resting electrocardiogram (ECG) in elite female handball players compared to non-athlete female subjects. Potential changes will be explored to see if they could be explained by differences in cardiac dimensions and exercise hours.

Materials and methods

A cross-sectional study of 33 elite female team handball players compared to 33 sex and age-matched, non-athletic controls (age range 18-26 years) was performed. All participants underwent a resting 12-lead ECG and an echocardiographic examination. ECG variables for left ventricular hypertrophy and durations were evaluated and adjusted for cardiac dimensions and exercise hours using ANCOVA analysis. A linear regression analysis was used to describe relation between echocardiographic and ECG measures and exercise hours.

Results

The female handball players had larger cardiac dimensions and significantly lower heart rate and QTc duration (Bazett's formula) as well as increased QRS and QT durations compared to controls. The 12-lead sum of voltage and the 12-lead sum of voltage ∗ QRS were significantly higher among handball players. Changes in ECG variables reflecting the left ventricle could in part be explained by left ventricular size and exercise hours. Correlation with exercise hours were moderately strong in most of the echocardiographic measures reflecting left ventricular (LV), left ventricular mass (LVM), left atrium (LA) and right atrium (RA) size. Poor to fair correlations were seen in the majority of ECG measures.

Conclusions

Female team handball players had altered ECGs, longer QRS and QT durations, higher 12-lead sum of voltage and 12-lead sum of voltage ∗ QRS as well as shorter QTc (Bazett's formula) duration compared to non-athletic controls. These findings could only partly be explained by differences in left ventricular size. Despite larger atrial size in the athletes, no differences in P-wave amplitude and duration were found on ECG. This suggest that both structural, and to some degree electrical remodeling, occur in the female team handball players' heart and highlight that a normal ECG does not rule out structural adaptations. The present study adds knowledge to the field of sports cardiology regarding how the heart in female team handball players adapts to this type of sport.

Dohongsamul-tang inhibits cardiac remodeling and fibrosis through calcineurin/NFAT and TGF-β/Smad2 signaling in cardiac hypertrophy

ETHNOPHARMACOLOGICAL RELEVANCE

Dohongsammul-tang (DH) is a Korean traditional herbal medicine used to alleviate symptoms caused by extravasated blood. It is known to protect against cardiovascular diseases and promote blood circulation by activating blood circulation to dispel blood stasis. The DH based on the characteristics of its medicinal properties has discovered the potential of alleviating cardiac hypertrophy. Therefore, this study was performed to verify the pharmacological effect of DH on improving cardiovascular disorders and to demonstrate its mutual improvement effect on renal function. Furthermore, aim of this study is founding the new potential beyond the traditional medicinal efficacy of DH, a traditional medicine.

AIM OF THE STUDY

In cardiovascular disease, cardiac hypertrophy refers to a change in the shape of the heart's structure due to pressure overload. It is known that an increase in myofibrils causes thickening of the heart, resulting in high blood pressure. Therefore, suppressing cardiac hypertrophy may be a major factor in lowering the morbidity, mortality, and heart failure associated with cardiovascular disease. Therefore, the study was performed to investigate whether DH, traditionally used, has effects on improving and alleviating cardiac injury and fibrosis caused by cardiac hypertrophy.

MATERIALS AND METHODS

Dohongsamul-tang was composed of 6 herbal medicine and each material were boiled with 4 L distilled water for 2 h. The mixture for dohongsamul-tang centrifuged at 3000 rpm for 10 min and concentrated. The concentrated dohongsamul-tang extraction freeze-dried and sotred at 70 °C. The powder of dohongsamul-tang was diluted with distilled water and administered orally. In this study, pressure overload was induced by tying the transverse aortic arch, which is connected to the left ventricle, to the thickness of a 27G needle by performing a surgical operation. The resulting cardiac hypertrophy and heart remodeling was induced and maintained for 8 weeks.

RESULTS

The study administered propranolol and dohongsamul-tang orally for 10 weeks to investigate their effects on cardiac hypertrophy induced by transverse aortic contraction (TAC) surgery. Results showed that TAC group increased the left ventricle weight and decreased cardiac function, but dohongsamul-tang treatment attenuated these effects. The pressure-volume curve experiment revealed that dohongsamul-tang improved cardiovascular function, which was worsened by TAC group. Dohongsamul-tang treatment also downregulated collagen I and III through the TGF-β/Smad2 signaling pathway and improved hematological biomarkers of cardiac hypertrophy. In addition, dohongsamul-tang treatment improved renal function-related biomarkers, such as blood creatinine, blood urea nitrogen, and neutrophil gelatinase-associated lipocalin, which were increased by TAC-induced cardiac hypertrophy.

CONCLUSIONS

Taken together, dohongsamul-tang treatment inhibited cardiac remodeling due to pressure overload in the TAC-induced cardiac hypertrophy model, and this effect is thought to be manifested by improving the functional and morphological changes through the calcineurin/NFATc4 and reducing the cardiac fibrosis by suppressing TGF-β/Smad2 signaling pathways.

Seamens' Sign: a novel electrocardiogram prediction tool for left ventricular hypertrophy

Introduction

Patients with left ventricular hypertrophy (LVH) diagnosed by electrocardiogram (ECG) have increased mortality and higher risk for life-threatening cardiovascular disease. ECGs offer an opportunity to identify patients with increased risk for potential risk-modifying therapy. We developed a novel, quick, easy to use ECG screening criterion (Seamens' Sign) for LVH. This new criterion was defined as the presence of QRS complexes touching or overlapping in two contiguous precordial leads.

Methods

This study was a retrospective chart review of 2,184 patient records of patients who had an ECG performed in the emergency department and a transthoracic echocardiogram performed within 90 days. The primary outcome was whether Seamens' Sign was noninferior in confirming LVH compared to other common diagnostic criteria. Test characteristics were calculated for each of the LVH criteria. Inter-rater agreement was assessed on a random sample using Cohen's Kappa.

Results

Median age was 63, 52% of patients were male and there was a 35% prevalence of LVH by transthoracic echocardiogram (TTE). Nine percent were positive for LVH on ECG based on Seamens' Sign. Seamens' Sign had a specificity of 0.92. Tests assessing noninferiority indicated Seamens' Sign was non-inferior to all criteria (p < 0.001) except for Cornell criterion for women (p = 0.98). Seamens' Sign had 90% (0.81-1.00) inter-rater agreement, the highest of all criteria in this study.

Conclusion

When compared to both the Sokolow-Lyon criteria and the Cornell criterion for men, Seamens' Sign is noninferior in ruling in LVH on ECG. Additionally, Seamens' Sign has higher inter-rater agreement compared to both Sokolow-Lyon criteria as well as the Cornell criteria for men and women, perhaps related to its ease of use.

Low QRS Voltage in Limb Leads Indicates Accompanying Precordial Voltage Attenuation Resulting in Underestimation of Left Ventricular Hypertrophy

Low QRS voltage (LQRSV) in electrocardiography (ECG) often occurs in limb leads without apparent cause. However, its clinical significance is obscure in healthy populations. We reviewed patients aged over 60 who were scheduled for non-cardiac surgery in two hospitals. Patients underwent pre-operative ECG, echocardiography, pulmonary function test, and chest X-ray. Patients with LQRSV isolated to limb leads and patients without LQRSV were selected from separate hospitals. Among the 9832 patients screened in one hospital, 292 (3.0%) showed LQRSV in limb leads. One-hundred and ninety-four without LQRSV were selected as the control from the 216 patients screened at the other hospital. For primary analysis, patients with structural heart disease or classic etiologies of LQRSV were excluded. Patients with LQRSV had a higher proportion of male and a greater body mass index. Precordial QRS voltages were smaller, whereas left ventricular mass index and the prevalence of echocardiographic left ventricular hypertrophy (LVH) was higher in patients with LQRSV than in those without. Consequentially, diagnostic performance of precordial voltage criteria for LVH was particularly poor in patients with LQRSV in limb leads. LQRSV in limb leads frequently occurs without apparent etiologies. ECG voltage criteria may underestimate LVH in a relatively healthy population with LQRSV in limb leads.

Impact of the distance from the chest wall to the heart on surface ECG voltage in athletes

Objective

Available ECG criteria for detection of left ventricular (LV) hypertrophy have been reported to have limited diagnostic capability. Our goal was to describe how the distance between the chest wall and the left ventricle determined by echocardiography affected the relationship between ECG voltage and LV mass (LVM) in athletes.

Methods

We retrospectively evaluated digitised ECG data from college athletes undergoing routine echocardiography as part of their preparticipation evaluation. Along with LV mass and volume, we determined the chest wall–LV distance in the parasternal short-axis and long-axis views from two-dimensional transthoracic echocardiographic images and explored the relation with ECG QRS voltages in all leads, as well as summed voltages as included in six major ECG-LVH criteria.

Results

239 athletes (43 women) were included (age 19±1 years). In men, greater LV–chest wall distance was associated with higher R-wave amplitudes in leads aVL and I (R=0.20 and R=0.25, both p<0.01), while in women greater distance was associated with higher R-amplitudes in V5 and V6 (R=0.42 and R=0.34, both p<0.01). In women, the chest wall–LV distance was the only variable independently (and positively) associated with R V5 voltage, while LVM, height and weight contributed to the relationship in men.

Conclusions

The chest wall–LV distance was weakly associated with ECG voltage in athletes. Inconsistent associations in men and women imply different intrathoracic factors affecting impedance and conductance between sexes. This may help explain the poor relationship between QRS voltage and LVM in athletes.