Electrocardiographic abnormalities in elite high school athletes: comparison to adolescent hypertrophic cardiomyopathy.

BACKGROUND: In athletes, ECG changes from physiological cardiac remodelling are common but can overlap with findings from a pathological disorder. We compared ECG findings in a group of elite high school athletes to a cohort of adolescents with hypertrophic cardiomyopathy (HCM). METHODS/RESULTS: We prospectively performed 15-lead ECGs and echocardiograms in 147 elite high school athletes. Student-athlete ECGs were compared in blinded fashion to ECGs of 148 adolescents with HCM of similar age and ethnicity. Standard ECG hypertrophy criteria and established expert opinion guidelines (European Society of Cardiology, ESC and Seattle criteria) were analysed. All student-athletes had normal echocardiograms. Overall, 77/147 (52%) of student-athletes met standard ECG criteria for ventricular hypertrophy compared to 126/148 (85%) adolescents with HCM (p<0.0001). There were 112/148 (76%) adolescents with HCM who had pathological Q-waves, T-wave inversion and/or ST-segment depression compared to 1/147 (1%) athletes (p<0.0001). Most patients with HCM (84%, 124/148) had ≥1 abnormal ECG finding(s) according to Seattle criteria, compared to 1% of student-athletes (2/147). Similarly, 130/148 (88%) patients with HCM met group-2 ESC criteria (abnormal), compared to 36/147 (24%) student-athletes (p<0.0001). CONCLUSIONS: Over 50% of elite high school athletes with echocardiographically confirmed normal hearts satisfied standard voltage criteria for ventricular hypertrophy. Pathological Q-waves, T-wave inversion or ST-segment depression were most helpful in distinguishing adolescents with HCM from normals. Both ESC and Seattle criteria successfully stratified the student-athlete and HCM cohorts, however each had a false-negative rate >10% for the HCM cohort. The Seattle criteria demonstrated a significantly lower false-positive rate (1%) than the ESC criteria (24%).

Surgical unroofing of anomalous aortic origin of a coronary artery: a single-center experience.

BACKGROUND: Anomalous aortic origin of a coronary artery (AAOCA) has been associated with myocardial ischemia and sudden death. The optimal management of patients with AAOCA is controversial. We examined our experience with surgical unroofing of AAOCA to determine the midterm effect of surgical repair. METHODS: From October 1992 through December 2011, 75 patients with AAOCA underwent surgical unroofing. RESULTS: Mean age was 39.6 ± 19.6 years; 23 patients (32%) were aged younger than 30 years. Angina, shortness of breath, or syncope was present in 55 patients (72%); 2 (3%) had history of sudden cardiac arrest. Of 40 patients (53%) who had preoperative stress tests, results were abnormal in 20 (50%). Coronary or computed tomography angiography demonstrated an anomalous right coronary artery (RCA) arising from the left sinus in 69 patients (92%) and the left main coronary artery arising from the right sinus in 6 (8%). Two patents (3%) were referred for recurrent anginal symptoms after previous RCA bypass with the right internal mammary artery. Minimally invasive partial upper sternal split was performed in 17 patients (22%). Two patients (3%) needed right internal mammary artery-to-RCA grafting due to flow acceleration at the RCA ostium. There were no early deaths. One late death (1%) occurred related to noncardiac causes. At follow-up (mean, 18 months; maximum, 7 years), all patients remained free of cardiac symptoms. CONCLUSIONS: Surgical unroofing of AAOCA is associated with low morbidity and mortality. At intermediate follow-up, resolution of symptoms and freedom from sudden death can be expected. The threshold for offering intervention should be low.

Pitfalls in diagnosis: suspected anomalous origin of the right coronary artery from the pulmonary artery.

Anomalous coronary arteries are rare in the general population. We report the case of a term neonate who underwent an echocardiogram to evaluate a possible patent ductus arteriosus. Unexpectedly, an apparent anomalous origin of the right coronary artery from the main pulmonary artery was detected by surface 2-dimensional transthoracic echocardiography and color-flow Doppler imaging. Because ventricular size and function were normal, the patient ultimately underwent cardiac catheterization to verify the anatomy before proposed surgery. Angiograms showed that the right coronary artery arose from the left anterolateral portion of the mid-ascending aorta. The patient did not require surgery. This case report illustrates pitfalls that can occur in the diagnosis of coronary artery anomalies.

The diagnostic utility of recovery phase QTc during treadmill exercise stress testing in the evaluation of long QT syndrome.

BACKGROUND: Nearly 40% of patients with long QT syndrome (LQTS) can have a nondiagnostic QTc at rest. Treadmill and cycle exercise stress testing are used in the diagnostic evaluation of LQTS. OBJECTIVE: The purpose of this study was to determine the diagnostic significance of peak exercise and recovery phase QTc values during treadmill stress testing in LQTS. METHODS: An Institutional Review Board-approved, retrospective analysis was performed on the treadmill stress tests in 243 patients including 82 LQT1, 55 LQT2, 18 LQT3, and 88 genotype-negative patients dismissed as normal. Blinded to genotype, QTc was calculated at rest, peak exercise, and 1, 2, 3, 4, and 5 minutes of recovery. RESULTS: Compared with those dismissed as normal, the average QTc was greater at all scored stages in LQT1 and LQT3 patients and at all stages in LQT2 patients except peak exercise and 1 minute of recovery (P < .01). Either an absolute QTc ≥ 460 ms during the recovery phase or a maladaptive, paradoxical increase in QTc, defined as QTc recovery--QTc baseline ≥ 30 ms (ΔQTc), distinguished patients with either manifest or concealed LQT1 from all other subsets (P < .0001). The presence of beta-blockers did not blunt these abnormal repolarization profiles. CONCLUSION: Treadmill stress testing can unmask patients with concealed LQTS, particularly LQT1, with good diagnostic accuracy.

Implantable cardioverter defibrillator therapy for congenital long QT syndrome: a single-center experience.

BACKGROUND: Long QT syndrome's (LQTS) marked heterogeneity necessitates both evidence-based and individualized therapeutic approaches. OBJECTIVE: This study sought to analyze a single LQTS specialty center's experience regarding the relationship between risk factors and appropriate ventricular fibrillation (VF)-terminating therapies among LQTS patients treated with an implantable cardioverter-defibrillator (ICD). METHODS: An internal review board-approved, retrospective analysis of the electronic medical records of 459 patients with genetically confirmed LQTS including the 51 patients (14 LQT1, 22 LQT2, and 15 LQT3) who received an ICD from 2000 to 2010 was performed. RESULTS: Twelve patients (24%, 4 LQT1, 8 LQT2) experienced an appropriate, VF-terminating therapy with an average follow-up of 7.3 years, including 7 of 17 LQT2 female patients but none of the 15 LQT3 patients. Conversely, 15 (29%) patients (8 LQT3) have experienced an inappropriate shock. Secondary prevention indications (P = .008), non-LQT3 genotype (P = .02), QTc ≥ 500 ms (P = .0008), documented syncope (P = .05), documented torsades de pointes (P = .003), and a negative family history (P = .0001) were most predictive of an appropriate therapy. Importantly, no LQT-related deaths have occurred among the 408 non-ICD-treated patients. CONCLUSION: The vast majority of LQTS patients can be treated effectively without an ICD. Potentially life-saving therapies were rendered at a 5% to 6% per year rate among those selected for ICD therapy; similar inappropriate shock frequencies were also noted. Secondary prevention, genotype, and QTc predicted those most likely to receive appropriate therapy. Although the ICD implant frequency is greatest among LQT3 patients, the greatest "save" rate has occurred among LQT2 women, who were assessed to be at high risk.

Ventricular ectopy during treadmill exercise stress testing in the evaluation of long QT syndrome.

BACKGROUND: Long QT syndrome (LQTS) can present with sudden death during exertion. OBJECTIVE: The purpose of this study was to determine the diagnostic importance of exercise-induced ventricular ectopy in the evaluation of LQTS. METHODS: From 1998 to 2006, 381 patients with a referral diagnosis of LQTS underwent a treadmill exercise stress test. An investigator blinded to both genotype and rendered diagnosis scored the stress tests for the presence of exercise-induced ventricular ectopy. RESULTS: The dismissal diagnosis was LQTS in 177 (46%), catecholaminergic polymorphic ventricular tachycardia (CPVT) in 16, miscellaneous cardiac disease in 17, and normal in 171. Exercise-induced ventricular ectopy was detected in 107 (28%) patients. However, only 34 patients (9% overall) had exercise-induced ventricular ectopy greater than single premature ventricular contractions (PVCs). Among the 171 patients dismissed as normal, only 2% had ectopy greater than single PVCs. Among the genotype-positive LQTS patients, no significant ectopy was recorded in 80 with LQT1, compared to 5 (8%) patients with LQT2 and 3 (20%) patients with LQT3 (P <.0001). In contrast, exercise-induced ventricular ectopy beyond single PVCs was far more common among patients with CPVT (14/16 [88%]; P <.0001) and included PVCs in bigeminy in 13 (81%), couplets in 7 (47%), and nonsustained ventricular tachycardia in 3 (19%). Of note, bidirectional VT was not present in any of the 16 patients diagnosed with CPVT, including the 10 with genetically proven, RYR2-mediated CPVT. CONCLUSION: Exercise-induced ventricular ectopy exceeding single PVCs was observed in less than 10% of patients referred for LQTS evaluation, including 2% of patients ultimately dismissed as normal. Exercise-induced bigeminy is strongly associated with the presence of significant cardiovascular disease but is far more likely to indicate CPVT than LQTS.