Variability in interpretation of the electrocardiogram in athletes: Another limitation in pre-competitive screening

INTRODUCTION

Assessment of the electrocardiogram (ECG) in athletes remains controversial, with lack of standardization and difficulty in applying specific criteria in its interpretation. The purpose of this study was to assess variability in the interpretation of the ECG in athletes.

METHODS

Twenty ECGs of competitive athletes were assessed by cardiologists and cardiology residents, 11 of them normal or with isolated physiological changes and nine pathological. Each ECG was classified as normal/physiological or pathological, with or without the use of specific interpretation criteria.

RESULTS

The study presents responses from 58 physicians, 42 (72.4%) of them cardiologists. Sixteen (27.6%) physicians reported that they regularly assessed athletes and 32 (55.2%) did not use specific ECG interpretation criteria, of which the Seattle criteria were the most commonly used (n=13). Each physician interpreted 15±2 ECGs correctly, corresponding to 74% of the total number of ECGs (variation: 45%-100%). Interpretation of pathological ECGs was correct in 68% (variation: 22%-100%) and of normal/physiological in 79% (variation: 55%-100%). There was no significant difference in interpretation between cardiologists and residents (74±10% vs. 75±10%; p=0.724) or between those who regularly assessed athletes and those who did not (77±12% vs. 73±9%; p=0.286), but there was a trend for a higher rate of correct interpretation using specific criteria (77±10% vs. 72±10%; p=0.092). The reproducibility of the study was excellent (intraclass correlation coefficient=0.972; p<0.001).

CONCLUSIONS

A quarter of the ECGs were not correctly assessed and variability in interpretation was high. The use of specific criteria can improve the accuracy of interpretation of athletes' ECGs, which is an important part of pre-competitive screening, but one that is underused.

Benign and pathological electrocardiographic changes in athletes

Sudden cardiac death is the leading cause of death in athletes during sport. It is a tragic event that generates significant media attention and discussion throughout society as to whether everything possible had been done to prevent it. Regular physical exercise causes cardiac remodeling at both the mechanical and electrical level, known as athlete's heart, resulting in an electrocardiogram (ECG) considered abnormal compared with the ECGs of the general population. Some of these electrocardiographic changes are considered normal or physiological in athletes, while others suggest underlying cardiac disease with the potential to cause sudden cardiac death. There is thus an urgent need to define the electrocardiographic patterns that allow or prohibit participation in sports, and to differentiate them in terms of gender, ethnicity and age. The purpose of this review is to present the latest data on the electrocardiographic changes considered benign or pathological that are typically found in athletes and to critically analyze the most recent criteria for classifying ECGs in this population (the Seattle criteria), comparing them with previous guidelines and with the latest studies on the subject. This article also examines the question of including ECGs in pre-participation screening programs, the US and European approaches to the subject, and the most up-to-date data on the sensitivity, specificity and cost-effectiveness of the ECG in athletes.

Natural history of Brugada syndrome in a patient with congenital heart disease

Risk stratification of sudden death in patients with Brugada syndrome (BrS) is a controversial issue, and there is currently no consensus on the best method. Examination of data from the natural history of the disease is of fundamental importance and may help to identify relatives at risk. At the same time, study of the genetic mutations responsible for the disease may also contribute to risk stratification of the syndrome, enabling identification of asymptomatic relatives carrying mutations. This paper presents the case of a young man, aged 26, monitored as a pediatric cardiology outpatient from birth for a simple structural heart defect not requiring surgery. Analysis of the evolution of the patient's electrocardiogram revealed the appearance, at the age of 20, of a pattern compatible with type I BrS. Following an episode of syncope and induction of polymorphic ventricular tachycardia in the electrophysiological study, a cardioverter-defibrillator was implanted. One year later, a single shock terminated an episode of ventricular fibrillation. A molecular study of the SCN5A gene identified a rare mutation, c.3622G>T (p.Glu1208X), recently described and associated with more severe phenotypes in patients with BrS, as in the case presented.

Electrocardiographic changes in dermatomyositis and polymyositis

INTRODUCTION

Cardiac involvement is frequent in inflammatory myopathies. Electrocardiogram (ECG) may show evidence of this involvement and its changes should be well-known and described.

OBJECTIVES

Due to the lack of studies in the literature, we conducted an analysis of the ECG findings in patients with dermatomyositis (DM) and polymyositis (PM), comparing them with a control group.

METHODS

This cross-sectional study compared the ECG of 86 individuals with no rheumatic disorders (controls) with 112 patients (78 DM and 34 PM), during 2010-2013. The ECG findings between DM and PM were also compared.

RESULTS

Demographic characteristics, comorbidities and ECG abnormalities were similar between controls and patients (p>0.05), except for a higher frequency of left ventricular hypertrophy (LVH) in patients (10.7% vs. 1.2%, p=0.008). Demographic characteristics, comorbidities, clinical and laboratory manifestations, were also similar between the groups PM and DM, except for the presence of cutaneous lesions only in DM. One-third of the patients had ECG abnormalities, which were more prevalent in PM than DM (50% vs. 24.4%, p=0.008). LVH, left atrial enlargement, rhythm and conduction abnormalities were more frequent in PM than DM (p<0.05 for all), especially the left anterior fascicular block.

CONCLUSIONS

We showed distinct ECG changes between DM and PM and a higher frequency of LVH in patients compared to controls. Investigation of cardiac involvement should be considered even in asymptomatic patients, especially PM. Further studies are necessary in order to determine the correlation of ECG findings with other complementary tests, clinical manifestations, disease activity and progression to other cardiac diseases.

Isolated papillary muscle hypertrophy: A gap in our knowledge of hypertrophic cardiomyopathy?

Increased thickness of left ventricular walls is the predominant characteristic and one of the diagnostic criteria of hypertrophic cardiomyopathy (HCM). This case illustrates an uncommon but important finding of isolated hypertrophy of the papillary muscles (PMs), observed in a young woman in whom an abnormal electrocardiogram was initially detected. During the investigation isolated PM hypertrophy was identified. The structural characteristics of the PMs have received scant attention in this setting and there is little information in the literature on this entity, whose real prevalence and clinical significance remain to be determined. The available information relates solitary PM hypertrophy with an early form or a different pattern of HCM. In this case PM hypertrophy was only detected due to the finding of an abnormal electrocardiogram, which prompted further diagnostic tests and a search for possible etiologies.

The value of electrocardiography for differential diagnosis in wide QRS complex tachycardia

Correct diagnosis in wide QRS complex tachycardia remains a challenge. Differential diagnosis between ventricular and supraventricular tachycardia has important therapeutic and prognostic implications, and although data from clinical history and physical examination may suggest a particular origin, it is the 12-lead surface electrocardiogram that usually enables this differentiation. Since 1978, various electrocardiographic criteria have been proposed for the differential diagnosis of wide complex tachycardias, particularly the presence of atrioventricular dissociation, and the axis, duration and morphology of QRS complexes. Despite the wide variety of criteria, diagnosis is still often difficult, and errors can have serious consequences. To reduce such errors, several differential diagnosis algorithms have been proposed since 1991. However, in a small percentage of wide QRS tachycardias the diagnosis remains uncertain and in these the wisest decision is to treat them as ventricular tachycardias. The authors' objective was to review the main electrocardiographic criteria and differential diagnosis algorithms of wide QRS tachycardia.

Discrepancy between stress electrocardiographic changes and nuclear myocardial perfusion defects in the prognostic assessment of patients with chest pain

OBJECTIVES

The aim of the present study was to determine the long-term prognostic value provided by the exercise electrocardiographic (ECG) response to nuclear myocardial perfusion imaging (MPI) in the evaluation of patients with chest pain, focusing on patients with a discrepancy between the two tests.

METHODS

A total of 1460 consecutive patients (777 female; 62.6 ± 11.4 years) undergoing exercise myocardial single-photon emission computed tomography (SPECT) were included. The endpoint was the occurrence of acute coronary syndrome, heart failure or cardiac death during follow-up.

RESULTS

Ischemic ECG changes were observed during stress testing in 271 patients (18.5%) and 362 patients (24.7%) had positive (abnormal) exercise MPI results. There was a discrepancy between ECG and SPECT findings in 471 patients (32.2%). During the follow-up period (14.0-39.6 months), 224 patients (15.3%) presented cardiac events. The hazard ratios (HR) of ECG and MPI results to predict events were 1.506 (95% CI: 1.113-2.039) and 10.481 (95% CI: 7.799-14.080), respectively. In patients with negative MPI, the ECG response did not predict events (HR 1.214 [95% CI: 0.646-2.282]), the same as in patients with positive MPI (HR 1.203 [95% CI: 0.848-1.705]). Only in hypertensive patients with positive SPECT did the ECG show significant prognostic value (HR 1.937 [95% CI: 1.030-3.642]). In multivariate analysis, positive MPI proved an independent long-term prognostic factor (HR 10.536 [95% CI: 7.759-14.308]), but not ECG (HR 1.356 [95% CI: 0.994-1.850]).

CONCLUSION

MPI results (normal vs. abnormal) had strong predictive value and discrepant ECG results had no significant additive prognostic value.

An unusual ST-segment elevation: apical hypertrophic cardiomyopathy shows the ace up its sleeve

Apical hypertrophic cardiomyopathy is part of the broad clinical and morphologic spectrum of hypertrophic cardiomyopathy. We report a patient with electrocardiographic abnormalities in whom acute coronary syndrome was excluded and apical hypertrophic cardiomyopathy was demonstrated by careful differential diagnosis.