Prevalence and Clinical Significance of Electrocardiographic Complete Right Bundle Branch Block in Young Individuals

BACKGROUND AND AIMS

There is limited information on the clinical significance of complete right bundle branch block (CRBBB) in young individuals. The aim of this study was to determine the prevalence and significance of CRBBB in a large cohort of young individuals aged 14-35 years old.

METHODS

From 2008 to 2018, 104,369 consecutive individuals underwent a cardiovascular assessment with a health questionnaire, electrocardiogram, clinical consultation, and selective echocardiography. Follow-up was obtained via direct telephone consultations. Mean follow-up was 7.3 ± 2.7 years.

RESULTS

CRBBB was identified in 154 (0.1%) individuals and was more prevalent in males compared with females (0.20% vs. 0.06%; p<0.05) and in athletes compared with non-athletes (0.25% vs. 0.14%; p<0.05). CRBBB-related cardiac conditions were identified in 7 (5%) individuals (4 with atrial septal defect, 1 with Brugada syndrome, 1 with progressive cardiac conduction disease and 1 with atrial fibrillation). Pathology was more frequently identified in individuals with non-isolated CRBBB compared with individuals with isolated CRBBB (14% vs 1%; p < 0.05) and in individuals with a QRS duration of ≥130 milliseconds (ms) compared with individuals with a QRS of <130ms (10% vs 1%; p<0.05).

CONCLUSION

The prevalence of CRBBB in young individuals was 0.1% and was more prevalent in males and athletes. CRBBB-related conditions were identified in 5% of individuals and were more common in individuals with non-isolated CRBBB and more pronounced intraventricular conduction delay (QRS duration of ≥130ms). Secondary evaluation should be considered for young individuals with CRBBB with symptoms, concerning family history, additional electrocardiographic anomalies or significant QRS prolongation (≥130ms).

Prevalence and diagnostic significance of novel 12-lead ECG patterns following COVID-19 infection in elite soccer players

Background

Identification of athletes with cardiac inflammation following COVID-19 can prevent exercise fatalities. The efficacy of pre and post COVID-19 infection electrocardiograms (ECGs) for detecting athletes with myopericarditis has never been reported. We aimed to assess the prevalence and diagnostic significance of novel 12-lead ECG patterns following COVID-19 infection in elite soccer players.

Methods

We conducted a multicentre study over a 2-year period involving 5 centres and 34 clubs and compared pre COVID and post COVID ECG changes in 455 consecutive athletes. ECGs were reported in accordance with the International recommendations for ECG interpretation in athletes. The following patterns were considered abnormal if they were not detected on the pre COVID-19 infection ECG: (a) biphasic T-waves; (b) reduction in T-wave amplitude by 50% in contiguous leads; (c) ST-segment depression; (d) J-point and ST-segment elevation &gt;0.2 mV in the precordial leads and &gt;0.1 mV in the limb leads; (e) tall T-waves ≥1.0 mV (f) low QRS-amplitude in &gt;3 limb leads and (g) complete right bundle branch block. Athletes exhibiting novel ECG changes underwent cardiovascular magnetic resonance (CMR) scans. One club mandated CMR scans for all 28 (6%) athletes, despite the absence of cardiac symptoms or ECG changes.

Results

Athletes were aged 22±5 years (89% male and 57% white). 65 (14%) athletes reported cardiac symptoms. The mean duration of illness was 3±4 days. The post COVID ECG was performed 14±16 days following a positive PCR. 440 (97%) athletes had an unchanged post COVID-19 ECG. Of these, 3 (0.6%) had cardiac symptoms and CMRs resulted in a diagnosis of pericarditis. 15 (3%) athletes demonstrated novel ECG changes following COVID-19 infection. Among athletes who demonstrated novel ECG changes, 10 (67%) reported cardiac symptoms. 13 (87%) athletes with novel ECG changes were diagnosed with inflammatory cardiac sequelae; pericarditis (n=6), healed myocarditis (n=3), definitive myocarditis (n=2), and possible/probable myocarditis (n=2). The overall prevalence of inflammatory cardiac sequelae based on novel ECG changes was 2.8%. None of the 28 (6%) athletes, who underwent a CMR, in the absence of cardiac symptoms or novel ECG changes revealed any abnormalities. Athletes revealing novel ECG changes, had a higher prevalence of cardiac symptoms (67% v 12% p&lt;0.0001) and longer symptom duration (8±8 days v 2±4 days; p&lt;0.0001) compared with athletes without novel ECG changes. Among athletes without cardiac symptoms, the additional yield of novel ECG changes to detect cardiac inflammation was 20% (n=3).

Conclusions

3% of elite soccer players demonstrated novel ECG changes post COVID-19 infection, of which almost 90% were diagnosed with cardiac inflammation during subsequent investigation. Most athletes with novel ECG changes exhibited cardiac symptoms. Novel ECGs changes contributed to a diagnosis of cardiac inflammation in 20% of athletes without cardiac symptoms.

Funding Acknowledgement

Type of funding sources: None.

Results of a nationally implemented cardiac screening programme in elite cricket players in England and Wales

OBJECTIVES

We assessed the diagnostic yield and costs of an electrocardiogram-based national screening programme in elite cricket players and the incremental value of transthoracic echocardiography and periodic evaluation.

DESIGN

Cross-sectional study.

METHODS

Between 2008 and 2019, 1208 cricketers underwent screening with a health questionnaire, 12-lead electrocardiogram and cardiology consultation. Athletes with concerning findings underwent on-site transthoracic echocardiography and further investigations as necessary. In addition, despite a normal health questionnaire and electrocardiogram, 342 (28.3%) athletes had a transthoracic echocardiogram and 493 (40.8%) underwent repeat evaluations.

RESULTS

After initial evaluation, 47 (3.9%) athletes underwent on-site transthoracic echocardiography of whom 35 (2.8%) were referred for further evaluation. Four athletes (0.3%) were diagnosed with major cardiac conditions; hypertrophic cardiomyopathy (n = 1), arrhythmogenic cardiomyopathy (n = 1) and Wolff-Parkinson-White pattern (n = 2). Two athletes were identified with minor valvular abnormalities. Repeat evaluation of 493 athletes identified hypertrophic cardiomyopathy in a 22-year-old athlete, two years after his initial normal screening. During a follow-up of 5.8 ± 2.9 years no additional diagnoses or adverse cardiac events were reported. The cost of the electrocardiogram-based programme was £127,844, translating to £106 per athlete and £25,569 per major cardiac condition identified.Routine transthoracic echocardiography in 342 athletes identified two athletes with major cardiac conditions (bicuspid aortic valve with severe aortopathy and aortic regurgitation and an atrial septal defect associated with right ventricular volume overload) and 10 athletes with minor abnormalities.

CONCLUSIONS

An electrocardiogram-based national screening programme identified a major cardiac condition in 0.3% of athletes. Routine transthoracic echocardiography and periodic evaluation increased the diagnostic yield to 0.6%, at an incremental cost.

Determinants of high-risk coronary artery disease in ostensibly healthy male master endurance athletes

Background

Healthy male master endurance athletes have a greater prevalence of high coronary calcium (CAC) scores compared to healthy sedentary counterparts, and some demonstrate high-risk plaque features. A number of theories have been postulated but reasons remain unclear. Concurrently atherosclerotic coronary artery disease (CAD) is the most common cause of sudden cardiac death in male master athletes drawing much public and scientific interest and making this an important public health issue.

Purpose

To examine the relationship of age, resting systolic blood pressure (SBP), exercise dose and sporting discipline with high-risk CAD markers in male master endurance athletes.

Methods

A prospective study undertaken over 19 months evaluated 214 male master (40–65 years) endurance athletes, free from known cardiovascular risk factors, symptoms or relevant health conditions. Clinical evaluation included cardiopulmonary exercise test, resting blood pressure (BP) and coronary computed tomogram angiography (CCTA). CCTA assessed CAC score, significant stenosis, (&gt;50%) and plaque vulnerability markers. Exercise dose was defined by years of endurance exercise and average MET-hours/week (lifetime exercise volume multiplied by the metabolic equivalent scores). Resting BP was the average of 3 consecutive supine measures after at least 5 minutes rest.

Results

Athletes (mean age 51, SD 70.1) exercised for minimum 6 hours/week (median 8.5) for a median of 15 years (2–26). Almost half (60.2%) were multi-endurance athletes i.e. any combination swimming, cycling and running. The remainder were runners (22.4%) and cyclists (15.4%). Median Framingham risk score 3.2% (1.8–5.8). The mean resting BP was 129/80 mmHg and a quarter (26%) of athletes were hypertensive (≥140/90 mmHg) at rest. A CAC score &gt;100 Agatston units (AU) was present in 16% of athletes. There was a total of 15 stenotic lesions in 11 (5%) athletes. 13% had plaque vulnerability markers.

Logistic regression evaluated whether age, resting SBP, exercise dose measures and sporting discipline were predictive for a CAC score &gt;100 AU, significant stenosis and plaque vulnerability markers (table 1). CAC score was associated with age, years of endurance exercise and resting SBP. A Stenosis &gt;50% and plaque vulnerability markers were associated with resting SBP and cycling compared with all other sporting disciplines.

Conclusion

Despite correcting for age, higher exercise dose (years endurance exercise) is associated with CAC score &gt;100 AU but does not predict significant stenosis or plaque vulnerability markers. Resting SBP and cycling strongly predict high-risk disease. Cycling enables a greater intensity of exercise compared with other endurance sports, which may be associated with prolonged rises in SBP. Resting SBP and cycling are important determinants for high-risk CAD in middle-aged male endurance athletes and should be considered when risk stratifying in pre-participation evaluation.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): British Heart Foundation Clinical Research Training Fellowship

P3839Hypertension or hypertrophic cardiomyopathy? Using cardiovascular magnetic resonance imaging to unmask the great imitator

Background

Structural cardiac adaptations due to hypertension (HTN) present a diagnostic challenge when differentiating from hypertrophic cardiomyopathy (HCM), using traditional imaging techniques such as echocardiography (echo). Cardiac magnetic resonance imaging (CMR) offers reproducible anatomical, functional quantification and myocardial tissue characterisation which discriminates between hypertension and HCM.

Purpose

To identify hypertensive individuals with undiagnosed HCM using CMR imaging.

Methods

100 consecutive hypertensive patients underwent CMR at a tertiary centre dedicated blood pressure clinic (55% male, mean age 51 years). In keeping with ESC guidelines, end diastolic wall thickness (EDWT) ≥15mm identified individuals within the “grey zone” between hypertension and with a potential HCM diagnosis. 19 individuals were referred on to the dedicated inherited cardiac conditions clinic for further evaluation. Four patients expressed a definitive LV phenotype and were diagnosed with HCM. CMR parameters were compared in three groups: Hypertensive (HTN), “grey zone” Hypertensive (GZH) and HCM.

Results

CMR demonstrated end diastolic wall thickness (EDWT) >11 mm in 50% of hypertensives. 73% of the referred patients were Afro-Caribbean (AC) and all 4 HCM patients were AC. All referrals demonstrated EDWTs ≥14mm, 9 (47%) demonstrated late gadolinium enhancement of which 3 (16%) had HCM. Three had asymmetrical septal hypertrophy – 2 were in the HCM cohort and one underwent endomyocardial biopsy confirming HTN. Left ventricular mass index (LVMI) was significantly higher in GZH compared to HTN (p<0.0001) and in HCM compared to HTN (p=0.0004). EDWT was significantly greater in GZH compared to HTN (p<0.0001) and in HCM compared to HTN (p=0.0002). There was no significant difference in these parameters between GZH and HCM.

Table 1. P-values for CMR data in hypertensive (HTN), gray zone hypertensive (GZH) and hypertrophic cardiomyopathy (HCM) cohorts CMR Parameter HCM vs. HTN GZH vs. HTN GZH vs. HCM EDVI NS p=0.025 NS EDWT p=0.0002 p<0.0001 NS LVMI p=0.0004 p<0.0001 NS

Conclusion

This study reports a 4% prevalence of HCM among hypertensive patients - 20 x greater than in the general population - which would be left undiagnosed using echo alone. Screening hypertensive individuals with CMR is not routine but we advocate its use in these individuals especially in Afro Caribbeans and in those in the “grey zone”, to identify undiagnosed HCM, which has significant implications for lifestyle modification and family screening.

Acknowledgement/Funding

Cardiac Risk in the Young

Pre-participation cardiovascular screening: is community screening using hand-held cardiac ultrasound feasible?

We evaluated the feasibility and costs of utilising hand-held cardiac ultrasound (HHCU) as part of a community-based pre-participation cardiovascular screening programme. Ninety-seven school children were screened using a personal history, a physical examination, a resting 12-lead electrocardiogram (ECG) and a HHCU. A consultant cardiologist independently reviewed and reported the data. Previously undiagnosed cardiovascular abnormalities were identified in nine participants (9%). An additional three participants (3%) were diagnosed with hypertension. The nine abnormalities were identified at a cost of £460 per finding, with a cost of £43 per participant screened. The marginal cost of adding a HHCU to the personal history, physical examination and ECG was £16 per participant. Pre-participation screening in the community using hand-held echocardiography is practical and inexpensive. The additional sensitivity and specificity provided by the ultrasound may enhance screening programmes, thereby reducing false positives and the need for expensive follow-up testing.