| 1. |
- Hedman, Kristofer, et al.
(författare)
-
Impact of the distance from the chest wall to the heart on surface ECG voltage in athletes
- 2020
-
Ingår i: BMJ OPEN SPORT & EXERCISE MEDICINE. - : BMJ Publishing Group Ltd. - 2055-7647. ; 6:1
-
Tidskriftsartikel (refereegranskat)abstract
- ObjectiveAvailable 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.MethodsWe 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.Results239 athletes (43 women) were included (age 191years). In men, greater LV-chest wall distance was associated with higher R-wave amplitudes in leads aVL and I (R=0.20and R=0.25, both p<0.01), while in women greater distance was associated with higher R-amplitudes in V5 and V6 (R=0.42and 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.ConclusionsThe 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.
|
|
| 2. |
- Hedman, Kristofer, 1984-, et al.
(författare)
-
Limitations of Electrocardiography for Detecting Left Ventricular Hypertrophy or Concentric Remodeling in Athletes
- 2020
-
Ingår i: American Journal of Medicine. - : Elsevier. - 0002-9343 .- 1555-7162. ; 133:1, s. 123-132.e8
-
Tidskriftsartikel (refereegranskat)abstract
- BackgroundElectrocardiography (ECG) is used to screen for left ventricular hypertrophy (LVH), but common ECG-LVH criteria have been found less effective in athletes. The purpose of this study was to comprehensively evaluate the value of ECG for identifying athletes with LVH or a concentric cardiac phenotype.MethodsA retrospective analysis of 196 male Division I college athletes routinely screened with ECG and echocardiography within the Stanford Athletic Cardiovascular Screening Program was performed. Left-ventricular mass and volume were determined using echocardiography. LVH was defined as left ventricular mass (LVM) > 102 g/m²; a concentric cardiac phenotype as LVM-to-volume (M/V) ≥ 1.05 g/mL. Twelve-lead electrocardiograms including high-resolution time intervals and QRS voltages were obtained. Thirty-seven previously published ECG-LVH criteria were applied, of which the majority have never been evaluated in athletes. C-statistics, including area under the receiver operating curve (AUC) and likelihood ratios were calculated.ResultsECG lead voltages were poorly associated with LVM (r = 0.18-0.30) and M/V (r = 0.15-0.25). The proportion of athletes with ECG-LVH was 0%-74% across criteria, with sensitivity and specificity ranging between 0% and 91% and 27% and 99.5%, respectively. The average AUC of the criteria in identifying the 11 athletes with LVH was 0.57 (95% confidence interval [CI] 0.56-0.59), and the average AUC for identifying the 8 athletes with a concentric phenotype was 0.59 (95% CI 0.56-0.62).ConclusionThe diagnostic capacity of all ECG-LVH criteria were inadequate and, therefore, not clinically useful in screening for LVH or a concentric phenotype in athletes. This is probably due to the weak association between LVM and ECG voltage.
|
|
