Athlete’s heart electrocardiogram mimicking hypertrophic cardiomyopathy

Highly trained athletes show a variety of electrocardiographic (ECG) changes, including a striking increase of R or S wave voltage, either flat or deeply inverted T waves, and deep Q waves, that suggest the presence of structural cardiovascular disease, such as hypertrophic cardiomyopathy or arrhythmogenic right ventricular cardiomyopathy, which represent the most common causes of sudden death in young competitive athletes. Despite a number of previous observational surveys, the determinants and clinical significance of these abnormal ECG patterns in trained athletes are still uncertain. Therefore, ECG patterns were compared with cardiac morphology (by echocardiography) in a large population of 1005 athletes, who were engaged in a variety of 38 sporting disciplines. We found abnormal ECGs in 40% of our athletes, but structural cardiac diseases were identified in only 5%. In the absence of cardiac disease, other determinants were recognized as responsible for abnormal ECG patterns, including the extent of morphologic cardiac remodeling, participation in an endurance type of sport, and male gender. Finally, a small but important subset of athletes showed striking ECG abnormalities that strongly suggested the presence of cardiovascular disease in the absence of pathologic cardiac conditions or morphologic changes, suggesting that these ECG alterations may be the consequence of athletic conditioning itself.     

The athlete's heart: remodeling, electrocardiogram and preparticipation screening

Highly trained athletes show morphologic cardiac changes (ie, athlete's heart) that are the consequence of several determinants, including type of sport, gender, and, possibly, inherited genetic factors. The extent of physiologic cardiac remodeling may occasionally be substantial in highly trained athletes and may raise a differential diagnosis with structural cardiac disease, such as cardiomyopathies. In addition, athletes demonstrate a spectrum of alterations in the 12-lead electrocardiogram (ECG) pattern, including marked increase in precordial R-wave or S-wave voltages, ST segment or T-wave changes, and deep Q waves suggestive of left ventricular hypertrophy, that may raise the possibility of pathologic heart condition, but have also been viewed as a consequence of the cardiac morphologic remodeling induced by athletic conditioning. To evaluate the clinical significance of these abnormal ECGs, the authors compared ECG patterns to cardiac morphology and function (assessed by two-dimensional echocardiography in individual athlete) in a large population of 1005 elite athletes engaged in a variety of sporting disciplines. Forty percent of the athletes had abnormal ECGs, and a subgroup of about 15% showed distinctly abnormal and often bizarre patterns highly suggestive of cardiomyopathies, such as hypertrophic cardiomyopathy, in the absence of pathologic cardiac changes. Such alterations are likely the consequence of athletic conditioning itself and represent another potential component of athlete's heart syndrome. However, such false-positive ECGs represent a potential limitation to the efficacy of routine ECG testing in the preparticipation cardiovascular screening of large athletic populations.     

Cardiovascular screening with electrocardiography and echocardiography in collegiate athletes

Background

Current guidelines for preparticipation screening of competitive athletes in the US include a comprehensive history and physical examination. The objective of this study was to determine the incremental value of electrocardiography and echocardiography added to a screening program consisting of history and physical examination in college athletes.

Methods

Competitive collegiate athletes at a single university underwent prospective collection of medical history, physical examination, 12-lead electrocardiography, and 2-dimensional echocardiography. Electrocardiograms (ECGs) were classified as normal, mildly abnormal, or distinctly abnormal according to previously published criteria. Eligibility for competition was determined using criteria from the 36^th Bethesda Conference on Eligibility Recommendations for Competitive Athletes with Cardiovascular Abnormalities.

Results

In 964 consecutive athletes, ECGs were classified as abnormal in 334 (35%), of which 95 (10%) were distinctly abnormal. Distinct ECG abnormalities were more common in men than women (15% vs 6%, P < .001) as well as black compared with white athletes (18% vs 8%, P < .001). Echocardiographic and electrocardiographic findings initially resulted in exclusion of 9 athletes from competition, including 1 for long QT syndrome and 1 for aortic root dilatation; 7 athletes with Wolff-Parkinson-White patterns were ultimately cleared for participation. (Four received further evaluation and treatment, and 3 were determined to not need treatment.) After multivariable adjustment, black race was a statistically significant predictor of distinctly abnormal ECGs (relative risk 1.82, 95% confidence interval, 1.22-2.73; P = .01).

Conclusions

Distinctly abnormal ECGs were found in 10% of athletes and were most common in black men. Noninvasive screening using both electrocardiography and echocardiography resulted in identification of 9 athletes with important cardiovascular conditions, 2 of whom were excluded from competition. These findings offer a framework for performing preparticipation screening for competitive collegiate athletes.     

Impact of physical deconditioning on ventricular tachyarrhythmias in trained athletes.

OBJECTIVES: The purpose of this research was to evaluate the impact of athletic training and, in particular, physical deconditioning, on frequent and/or complex ventricular tachyarrhythmias assessed by 24-h ambulatory (Holter) electrocardiogram (ECG). BACKGROUND: Sudden deaths in athletes are usually mediated by ventricular tachyarrhythmias. METHODS: Twenty-four hour ambulatory ECGs were recorded at peak training and after a deconditioning period of 19 +/- 6 weeks (range, 12 to 24 weeks) in a population of 70 trained athletes selected on the basis of frequent and/or complex ventricular tachyarrhythmias (i.e., > or =2,000 premature ventricular depolarization [PVD] and/or > or =1 burst of non-sustained ventricular tachycardia [NSVT]/24 h). RESULTS: A significant decrease in the frequency and complexity of ventricular arrhythmias was evident after deconditioning: PVDs/24 h: 10,611 +/- 10,078 to 2,165 +/- 4,877 (80% reduction; p < 0.001) and NSVT/24 h: 6 +/- 22 to 0.5 +/- 2, (90% reduction; p = 0.04). In 50 of the 70 athletes (71%), ventricular arrhythmias decreased substantially after detraining (to <500 PVDs/24 h and no NSVT). Most of these athletes with reduced arrhythmias did not have structural cardiovascular abnormalities (37 of 50; 74%). Over the 8 +/- 4-year follow-up period, each of the 70 athletes survived without cardiac symptoms. CONCLUSIONS: Frequent and/or complex ventricular tachyarrhythmias in trained athletes (with and without cardiovascular abnormalities) are sensitive to brief periods of deconditioning. In athletes with heart disease, the resolution of such arrhythmias with detraining may represent a mechanism by which risk for sudden death is reduced. Conversely, in athletes without cardiovascular abnormalities, reduction in frequency of ventricular tachyarrhythmias and the absence of cardiac events in the follow-up support the benign clinical nature of these rhythm disturbances as another expression of athlete's heart.     

Prolongation of the cardiac QTc interval in Turner syndrome

Anatomic anomalies of the cardiovascular system occur in approximately 50% of individuals with Turner syndrome (TS), with the specific genetic cause(s) for the heart defects still unknown. Because congenital heart disease may be associated with conduction system abnormalities, we compared electrocardiograms (ECGs) in 100 women with TS and 100 age-matched female controls. Women with TS were significantly more likely to demonstrate left posterior fascicular block (p < 0.005), accelerated AV conduction (p < 0.006), and T wave abnormalities (p < 0.006). The PR interval was significantly shorter (137 +/- 17 vs. 158 +/- 18 ms, p < 0.0001) and the rate-corrected QT interval (QTc) significantly longer in women with TS than in controls (423 +/- 19 ms vs. 397 +/- 18 ms; p < 0.0001). Twenty-one women with TS but no controls had a QTc greater than 440 ms. We found no statistically significant relation between body habitus, cardiac dimensions, evidence of congenital heart disease, or metabolic parameters and the incidence of ECG abnormalities or QTc duration in TS. Cardiac conduction and repolarization abnormalities appear to be intrinsic features of TS, suggesting that deletion of the second sex chromosome has more profound effects on the cardiovascular system than previously recognized, and that ECG analysis should be included in evaluating and monitoring patients with Turner syndrome.     

Marked ventricular repolarization abnormalities in highly trained athletes' electrocardiograms: clinical and prognostic implications

OBJECTIVE: We sought to study the functional, clinical and prognostic implications of marked repolarization abnormalities (MRA) sometimes seen in athletes' electrocardiograms (ECGs). BACKGROUND: The clinical meaning of ECG MRA in athletes is unknown. No relationship has been drawn between either training intensity or any particular type of sport and MRA. Athletes are usually symptom free and do not show any decrease in their physical performance. It is as yet unclear whether MRA may have a negative effect on the performance of such athletes in competitive sports. METHODS: We studied 26 athletes with MRA (negative T waves > or =2 mm in three or more ECG leads at rest). No athletes presented clinical symptoms of cardiac disease or decrease in their physical performance. Clinical and physical examinations, ECG at rest, exercise test and echocardiographic and antimyosin studies were performed in all athletes. Rest/exercise myocardial perfusion single-photon emission computed tomography studies were performed in 17 athletes. The follow-up ranged from 4 to 20 years (mean 6.7 years). RESULTS: Four athletes were excluded due to hypertrophic cardiomyopathy. Echocardiographic studies showed right and left normal ventricular dimensions for highly conditioned athletes. In the exercise test, heart rate was 166 +/- 12.4 beats/min, and exercise tolerance was 15.2 +/- 2.7 metabolic equivalents of the task. All athletes had ECG at rest simulating myocardial ischemia or "pseudoischemia" with a tendency to normalize during exercise. Myocardial perfusion studies were normal in the studied athletes. Antimyosin studies showed mild and diffuse myocardial radiotracer uptake in 15 athletes (68%). No adverse clinical events were observed in the follow-up. CONCLUSIONS: These results suggest that MRA have no clinical or pathological implications in athletes and should, therefore, not preclude physical training or participation in sporting events.     

Standardised pre-competitive screening of athletes in some European and African countries: the SMILE study

Most of the available data on the cardiovascular screening of athletes come from Italy, with fewer records being available outside of Italy and for non-Caucasian populations. The goals of the SMILE project (Sport Medicine Intervention to save Lives through ECG) are to evaluate the usefulness of 12-lead ECGs for the detection of cardiac diseases in athletes from three European countries and one African country and to estimate how many second-level examinations are needed subsequent to the initial screening in order to classify athletes with abnormal characteristics. A digital network consisting of Sport Centres and second and third opinion centres was set up in Greece, Germany, France and Algeria. Standard digital data input was carried out through the application of 12-lead ECGs, Bethesda questionnaires and physical examinations. Two hundred ninety-three of the 6,634 consecutive athletes required further evaluation, mostly (88.4 %) as a consequence of abnormal ECGs. After careful evaluation, 237 were determined to be healthy or apparently healthy, while 56 athletes were found to have cardiac disorders and were thus disqualified from active participation in sports. There was a large difference in the prevalence of diseases detected in Europe as compared with Algeria (0.23 and 4.01 %, respectively). Our data confirmed the noteworthy value of 12-lead resting ECGs as compared with other first-level evaluations, especially in athletes with asymptomatic cardiac diseases. Its value seems to have been even higher in Algeria than in the European countries. The establishment of a digital network of Sport Centres for second/third opinions in conjunction with the use of standard digital data input seems to be a valuable means for increasing the effectiveness of screening.     

Prevalence of abnormal electrocardiograms in a large, unselected population undergoing pre-participation cardiovascular screening.

AIMS: The implementation of 12-lead ECG in the pre-participation screening of young athletes is still controversial and number of issues are largely debated, including the prevalence and spectrum of ECG abnormalities found in individuals undergoing pre-participation screening. METHODS AND RESULTS: We assessed a large, unselected population of 32,652 subjects [26 050 (80%) males], prospectively examined in 19 clinics associated to Italian Sports Medicine Federation. Most were young amateur athletes, aged 8-78 years (median 17), predominantly students (68%), engaged predominantly in soccer (39%), volleyball or basketball (8% each), athletics (6%), cycling (5%), swimming (4%). The ECG patterns were evaluated according to commonly used clinical criteria. The 12-lead ECG patterns were considered normal in 28 799 of the 32 652 athletes (88.2%) and abnormal in 3853 (11.8%). The most frequent abnormalities included prolonged PR interval, incomplete right bundle branch block (RBBB) and early repolarization pattern (total 2280, 7.0%). Distinct ECG abnormalities included deeply inverted T-waves in > 2 precordial and/or standard leads (751, 2.3%), increased R/S wave voltages suggestive of LV hypertrophy (247, 0.8%), conduction disorders, i.e. RBBB (351, 1.0%), left anterior fascicular block (162, 0.5%), and left bundle branch block (19, 0.1%). Rarely, cardiac pre-excitation pattern (42, 0.1%) and prolonged QTc interval (1, 0.03%) were found. CONCLUSION: In a large, unselected population of young athletes undergoing pre-participation screening, the prevalence of markedly abnormal ECG patterns, suggestive for structural cardiac disease, is low (<5% of the overall population) and should not represent obstacle for implementation of 12-lead ECG in the pre-participation screening program.     

健康人高位右侧胸前导联Brugada心电图征调查

目的 初步了解我国健康人高位右侧胸前导联Brugada心电图征发生率及其意义。方法 对1005例健康体检者进行病史询问、体格检查、X线胸片、标准12导联和第二肋间右侧胸前导联心电图检查,按照欧洲心脏病学会制定的标准筛选Brugada心电图征。结果 排除4例器质性心脏病和心律失常患者后,共1001例（男877例,女124例）人选,年龄17～75（28．3±14．8）岁。标准导联心电图检查发现5例2型Brugada心电图征（0．5％）,第二肋间右侧胸前导联心电图检查发现47例Brugada心电图征（4．70％）,均为男性（2型40例,3型7例）。无不明原因晕厥或黑噱史,无猝死家族史。结论 对于症状不典型者,依据标准导联或高位右侧胸前导联2型或3型Brugada心电图征诊断Brugada综合征要慎重。     

Comparison of three ECG criteria for athlete pre-participation screening

Controversy regarding adding the ECG to the evaluation of young athletes centers on the implications of false positives. Several guidelines have been published with recommendations for criteria to distinguish between ECG manifestations of training and markers of risk for cardiovascular (CV) sudden death. With an athlete dataset negative of any CV related abnormalities on follow-up, we applied three athlete screening criteria to identify the one with the lowest rate of abnormal variants.MethodsHigh school, college, and professional athletes underwent 12 L ECGs as part of routine physicals. All ECGs were recorded and processed using CardeaScreen (Seattle, WA). The European (2010), Stanford (2011), and Seattle criteria (2013) were applied.ResultsFrom March 2011 to February 2013 1417 ECGs were collected. Mean age was 20 ± 4 years (14–35 years), 36% female, 38.5% non-white (307 high school, 836 college and 284 professional). Rate of abnormal variants differed by criteria, predominately due to variation in interval thresholds for QT interval and QRS duration. There was a four-fold difference in abnormal variants between European and Seattle criteria (26% v 6%).ConclusionThe Seattle criterion was the most conservative resulting in 78% fewer abnormal variants than the European criteria. Variation was most evident with thresholds for QT prolongation, short QT interval, and intraventricular conduction delay. Continued research is needed to further understand normal training related adaptations and to improve modern ECG screening criteria for athletes.     

Suspected cardiac syncope in elderly patients: use of the 12-lead electrocardiogram to select patients for holter monitoring.

BACKGROUND: Results of 24-hour Holter monitoring in elderly patients are often unhelpful, since the prevalence of asymptomatic arrhythmias increases and their prognostic significance is unclear. We investigated the value of the resting electrocardiogram (ECG) in predicting significant findings on 24-hour Holter recordings in those suspected of having cardiac syncope. OBJECTIVE: To see whether the resting 12-lead ECG can be used as a screening tool to select elderly patients suspected of having cardiac syncope for 24-hour ECG monitoring. METHOD: Comparison of resting 12-lead ECGs and 24-hour Holter tapes in 145 consecutive elderly outpatients suspected of having a cardiac cause for falls, dizziness, or syncope. RESULTS: Four of 30 normal ECGs (13%) showed an abnormality on Holter monitoring as compared with 55 of the 115 abnormal ECGs (47.8%; chi = 11.7143, p < 0.005). In the 'normal' group the 4 abnormal Holter recordings all showed short runs of supraventricular tachycardia, and no intervention resulted. The 115 abnormal resting ECGs showed either ischaemia (n = 27), dysrhythmia (n = 28), sinus bradycardia (n = 22), or conduction defects (n = 38). The 55 of these which showed abnormalities on Holter recordings occurred mostly where the resting ECG showed dysrhythmia (n = 14/28; 50%), bradycardia (n = 19/22; 86.4%), and conduction defect (n = 17/38; 44.7%). Seven patients had complete heart block on Holter, and all had conduction defects on resting ECG (p < 0.0004). Fifteen patients had pauses of longer than 3 s on Holter; all had conduction defect, bradycardia, or dysrhythmias on resting ECG (p < 0.0045). Sixteen patients were paced because of complete heart block or pauses on Holter recordings, and all had either bradycardia or conduction defects on resting ECG, resulting in complete resolution of their symptoms. CONCLUSIONS: Patients with suspected cardiac syncope and normal resting ECGs are unlikely to reveal significant abnormalities on single 24-hour Holter monitoring. Cardiac event recorder or prolonged Holter monitoring may be required in patients with strong clinical history. Those with abnormal ECGs, in particular sinus bradycardia and conduction defects, are highly likely to have significant abnormalities on 24-hour ECG monitoring.     

Cardiac screening before returning to elite sport after SARS-CoV-2 infection

BackgroundSARS-CoV-2 infection can induce cardiac damage. Therefore, in the absence of clear data, a cardiac evaluation was recommended for athletes before returning to play after recent SARS-CoV-2 infection.AimTo assess the proportion of anomalies detected by this cardiac screening.MethodsWe reviewed the medical files of elite athletes referred for cardiac evaluation before returning to play after a non-hospitalized SARS-CoV-2 infection (based on a positive polymerase chain reaction or antigen test) from March 2020 to July 2021 in 12 French centres.ResultsA total of 554 elite athletes (professional or national level) were included (median age 22 years, 72.0% male). An electrocardiogram (ECG), echocardiogram and exercise test were performed in 551 (99.5%), 497 (89.7%) and 293 (52.9%) athletes, respectively. We found anomalies with a potential link with SARS-CoV-2 infection in four ECGs (0.7%), three echocardiograms (0.6%) and three exercise tests (1.0%). Cardiac magnetic resonance imaging was performed in 34 athletes (6.1%), mostly due to abnormal first-line examinations, and was abnormal in one (2.9%). The rates of those abnormalities were not higher among athletes with cardiac symptoms or more severe forms of non-hospitalized SARS-CoV-2 infection. Only one athlete had a possible SARS-CoV-2 myocarditis and sport was temporally contraindicated. None had a major cardiac event declared during the follow-up.ConclusionThe proportion of cardiac involvement after non-hospitalized forms of SARS-CoV-2 infection in athletes are very low. Systematic cardiac screening before returning to play seems to be unnecessary.     

Spatial QRS-T angle predicts cardiac death in a general population.

AIMS: The aim of this study was to assess the prognostic importance of the spatial QRS-T angle for fatal and non-fatal cardiac events. METHODS AND RESULTS: Electrocardiograms (ECGs) were recorded in 6134 men and women aged 55 years and over from the prospective population-based Rotterdam Study. Spatial QRS-T angles were categorized as normal, borderline or abnormal. Using Cox's proportional hazards model, abnormal angles showed increased hazard ratios of cardiac death (age-and sex-adjusted hazard ratio 5.2 (95% CI 4.0-6.8)), non-fatal cardiac events (2.2 (1.5-3.1)), sudden death (5.6 (3.7-8.5)) and total mortality (2.3 (2.0-2.7)). None of the classical cardiovascular and ECG predictors provided larger hazard ratios. After adjustment for these predictors, the association of abnormal spatial QRS-T angles with all fatal study endpoints remained strong, but the association with non-fatal cardiac events disappeared. Computation of Akaike's information criterion showed that the angle contributed significantly to the prediction of all fatal endpoints by classical cardiovascular and ECG predictors. CONCLUSION: The spatial QRS-T angle is a strong and independent predictor of cardiac mortality in the elderly. It is stronger than any of the classical cardiovascular risk factors and ECG risk indicators and provides additional value to them in predicting fatal cardiac events.     

Preoperative electrocardiogram abnormalities do not predict postoperative cardiac complications in geriatric surgical patients

OBJECTIVES: Preoperative electrocardiograms (ECGs) are routinely performed on older patients before surgery. Whether patients with abnormalities on preoperative ECGs have an increased likelihood of developing postoperative cardiac complications is unknown. This study was designed to determine whether abnormalities on preoperative ECGs were predictive of postoperative cardiac complications. DESIGN: Prospective observational study. SETTING: One of the teaching hospitals of the University of California, San Francisco, Medical Center. PARTICIPANTS: Five hundred thirteen patients aged 70 and older undergoing noncardiac surgery. MEASUREMENTS: Preoperative ECGs were analyzed using the Minnesota Codes. Predefined preoperative risk factors and in-hospital postoperative cardiac complications were measured. The association between ECG abnormalities and postoperative cardiac complications was determined by multivariate logistic regression after controlling for clinical covariates. Odds ratios (ORs) and 95% confidence intervals (CIs) were reported. RESULTS: Three hundred eighty-six of 513 patients (75.2%) had at least one abnormality on their preoperative ECGs. On multivariate analysis, the predictors of postoperative cardiac complications included American Society of Anesthesiologists physical status classification of 3 or greater (OR = 2.5, 95%CI = 1.28-4.89, P = .007) and a history of congestive heart failure (OR = 2.1, 95% CI = 1.1-5.1, P = .034). The presence of abnormalities on preoperative ECGs was not associated with an increased risk of postoperative cardiac complications (OR = 0.63, 95% CI = 0.28-1.40, P = .26). CONCLUSION: Abnormalities on preoperative ECGs are common but are of limited value in predicting postoperative cardiac complications in older patients undergoing noncardiac surgery. These results suggest that obtaining preoperative ECGs based on an age cutoff alone may not be indicated, because ECG abnormalities in older people are prevalent but nonspecific and less useful than the presence and severity of comorbidities in predicting postoperative cardiac complications.     

ECG diagnostics in competitive athletes. Current implications for preparticipation screening

In young competitive athletes sudden cardiac death frequently occurs as a tragic first manifestation of clinically inapparent underlying structural or electrical cardiac disorders. An increased risk may be reflected by typical electrocardiogram (ECG) alterations preceding symptoms but a correct interpretation is often challenging due to a high prevalence of training-related ECG alterations in competitive athletes mimicking such disorders. Misinterpretation may thus result in either unnecessary disqualification from competitive sports or continuation despite an increased risk or extensive diagnostic work-ups yielding additional equivocal findings. However, as observed in large athlete cohorts in recent years a variety of ECG alterations, such as isolated increased QRS voltage, early repolarization, sinus bradycardia, first degree AV block or incomplete right bundle branch block, represent common variants of ECGs of athletes reflecting physiological and training-related cardiac adaptations. These alterations do not usually require further diagnostic evaluation. In contrast, alterations such as repolarization abnormalities, complete bundle branch block, prolonged QT intervals or pathological Q waves, are strongly suggestive of underlying disorders and require further evaluation even in asymptomatic athletes. Thus, the ECG plays a pivotal role in the prevention of sudden cardiac death in competitive athletes. The present article summarizes current recommendations for the interpretation of athlete ECGs regarding the differentiation between physiological or pathological cardiac adaptation.     

EKG-Diagnostik bei Leistungssportlern

In young competitive athletes sudden cardiac death frequently occurs as a tragic first manifestation of clinically inapparent underlying structural or electrical cardiac disorders. An increased risk may be reflected by typical electrocardiogram (ECG) alterations preceding symptoms but a correct interpretation is often challenging due to a high prevalence of training-related ECG alterations in competitive athletes mimicking such disorders. Misinterpretation may thus result in either unnecessary disqualification from competitive sports or continuation despite an increased risk or extensive diagnostic work-ups yielding additional equivocal findings. However, as observed in large athlete cohorts in recent years a variety of ECG alterations, such as isolated increased QRS voltage, early repolarization, sinus bradycardia, first degree AV block or incomplete right bundle branch block, represent common variants of ECGs of athletes reflecting physiological and training-related cardiac adaptations. These alterations do not usually require further diagnostic evaluation. In contrast, alterations such as repolarization abnormalities, complete bundle branch block, prolonged QT intervals or pathological Q waves, are strongly suggestive of underlying disorders and require further evaluation even in asymptomatic athletes. Thus, the ECG plays a pivotal role in the prevention of sudden cardiac death in competitive athletes. The present article summarizes current recommendations for the interpretation of athlete ECGs regarding the differentiation between physiological or pathological cardiac adaptation.     

Detection of hypertrophic cardiomyopathy is improved when using advanced rather than strictly conventional 12-lead electrocardiogram

Introduction

Twelve-lead electrocardiogram (ECG) is used to screen for hypertrophic cardiomyopathy (HCM), but up to 25% of HCM patients do not have distinctly abnormal ECGs, whereas up to 5% to 15% of healthy athletes do. We hypothesized that an approximately 5-minute resting advanced 12-lead ECG test (“A-ECG score”) could detect HCM with greater sensitivity than pooled conventional ECG criteria and distinguish healthy athletes from HCM with greater specificity.

Materials and methods

Five-minute 12-lead ECGs were obtained from 56 HCM patients, 56 age/sex-matched healthy controls, and 69 younger endurance-trained athletes. Electrocardiograms were analyzed using recently suggested pooled conventional ECG criteria and also A-ECG scoring techniques that considered results from multiple advanced and conventional ECG parameters.

Results

Compared with pooled criteria from the strictly conventional ECG, an A-ECG logistic score incorporating results from just 3 advanced ECG parameters (spatial QRS-T angle, unexplained portion of QT variability, and T-wave principal component analysis ratio) increased the sensitivity of ECG for identifying HCM from 89% (78%-96%) to 98% (89%-100%; P = .025), while increasing specificity from 90% (83%-94%) to 95% (92%-99%; P = .020).

Conclusions

Resting 12-lead A-ECG scores that are simultaneously more sensitive than pooled conventional ECG criteria for detecting HCM and more specific for distinguishing healthy athletes and other healthy controls from HCM can be constructed. Pending further prospective validation, such scores may lead to improved ECG-based screening for HCM.     

A prospective study on spontaneous fluctuations between diagnostic and non-diagnostic ECGs in Brugada syndrome: implications for correct phenotyping and risk stratification.

AIMS: Fluctuations between the diagnostic ECG pattern and non-diagnostic ECGs in patients with Brugada syndrome are known, but systematic studies are lacking. The purpose of this study was to prospectively evaluate the spontaneous ECG changes between diagnostic and non-diagnostic ECG patterns in patients diagnosed with Brugada syndrome. METHODS AND RESULTS: In 43 patients with Brugada syndrome (27 males; mean age 45+/-11 years), 310 resting ECGs were obtained during a median follow-up of 17.7 months. The ECGs were analysed for the presence of coved type, saddle-back type or no, respectively unspecific, changes. A coved-type ECG pattern with more than 2 mm ST-segment elevation in at least two right precordial leads was defined as diagnostic. The patients were compared for different clinical characteristics with respect to the pattern of fluctuations. Out of a total of 310 ECGs, 102 (33%) revealed a coved type, 91 (29%) a saddle-back type, and 117 (38%) a normal ECG. Fifteen patients (35%) initially presented with a diagnostic coved-type ECG. Fourteen patients (33%) with an initially coved-type ECG exhibited intermittently non-diagnostic ECGs during follow-up. Only one patient (2%) presented constantly with a coved-type ECG. Out of 28 patients (65%) with an initially non-diagnostic ECG, eight (19%) patients developed a diagnostic coved-type ECG during follow-up. Twenty patients (47%) revealed a coved-type ECG during ajmaline challenge, but never had a baseline coved-type ECG recorded. No significant differences were found in gender and clinical characteristics among patients with or without fluctuations between diagnostic and non-diagnostic basal ECGs. The rate of inducible ventricular fibrillation was significantly higher in patients with more than 50% coved-type ECGs than in patients with less than 50% diagnostic ECGs. CONCLUSION: The prevalence of fluctuations between diagnostic and non-diagnostic ECGs in patients with Brugada syndrome is high and may have an implication on the correct phenotyping and on the risk stratification in patients with Brugada syndrome without aborted sudden cardiac death. For correct phenotyping and risk stratification, repetitive ECG recordings seem to be mandatory.     

Relation of ECG changes to neurological outcome in patients with aneurysmal subarachnoid hemorrhage

BACKGROUND: Electrocardiographic (ECG) alterations occurring during the course of subarachnoid hemorrhage (SAH) have been described frequently, but the incidence, patterns, and prognostic significance are not well defined. This study was designed to investigate these features. METHODS: All patients admitted to a 31-bed department of intensive care between 1993 and 2000 with acute aneurysmal SAH documented by cerebral angiography or autopsy were included. Patient charts were reviewed retrospectively, and an observer blinded to the patients' clinical course and outcome reviewed the ECGs. In-hospital mortality and outcome as assessed by the Glasgow outcome score were noted. RESULTS: Of 159 patients (49.6 years [range: 20-75]) with acute SAH, 106 (66.7%) had abnormal ECGs (classified by an observer blinded to the patients' clinical course and outcome. Conduction abnormalities were present in 7.5%. Arrhythmias occurred in 30.2%. By univariate analysis, the presence of ST depression was related to outcome as assessed by the Glasgow Outcome Scale (GOS) (15% poor outcome [GOS 4-5] vs. 1% good outcome [GOS 1-3], p<0.05). However, by multivariate analysis, none of the ECG alterations was related to outcome. ST depression was related to the APACHE II score, Hunt and Hess scale, and the WFNS score. ECG abnormalities were not related to the development of vasospasm or increased intracranial pressure. CONCLUSIONS: In patients with acute aneurysmal SAH, repolarization abnormalities are the commonest ECG alterations, and ST depression is more common in patients with poor outcome. However, ECG alterations are not independently related to outcome.