Is a supraventricular tachycardia (SVT) burden of 15% acceptable in a 67‑year‑old athletic male?

Is a 15% SVT Burden Acceptable in a 67-Year-Old Athletic Male?

No, a 15% SVT burden is not acceptable and requires immediate comprehensive cardiac evaluation regardless of athletic status. This burden represents approximately 3.6 hours of SVT per 24 hours and is considered substantial, mandating urgent investigation to exclude life-threatening conditions and structural heart disease 1.

Why This Burden Demands Investigation

A 15% SVT burden is clinically significant and cannot be dismissed as benign:

• SVT in athletes is rare and always warrants investigation because it can be associated with life-threatening conditions including long-QT syndrome, Wolff-Parkinson-White syndrome, Brugada syndrome, myocarditis, congenital heart disease, and cardiomyopathies 1.
• Persistent SVT with rapid ventricular response over weeks to months can lead to tachycardia-mediated cardiomyopathy and subsequent heart failure 1, 2.
• Up to 64% of individuals with documented arrhythmias may be asymptomatic at initial evaluation; lack of symptoms does not guarantee a benign course 1.
• In athletes with frequent ectopy (>2,000 premature ventricular complexes per 24 hours), approximately 30% were found to have underlying structural heart disease 1.

Age-Specific Concerns in a 67-Year-Old

At age 67, coronary artery disease becomes the primary concern:

• For individuals ≥30 years old, coronary artery disease (CAD) is the most common cause of sudden cardiac death in athletes, making CAD assessment essential in this age group 1.
• Older patients are more prone to syncope or presyncope with SVT regardless of heart rate, and have a higher likelihood of underlying structural heart disease 3.
• Patients with structural heart disease have a higher risk of complications and this condition must be identified using echocardiography 3.

Required Immediate Diagnostic Workup

The following tests are mandatory first-line investigations:

Core Cardiac Imaging and Monitoring

• Transthoracic echocardiogram to detect structural heart disease, cardiomyopathies, or congenital abnormalities 1, 3.
• 12-lead ECG during tachycardia to identify the specific SVT mechanism (e.g., AV nodal re-entrant tachycardia, atrial tachycardia) 1.
• Extended ambulatory ECG monitoring during training and competition to characterize the arrhythmia, assess exercise-related changes, and exclude complex ventricular arrhythmias 1.

Exercise and Ischemia Assessment

• Exercise stress testing to evaluate for CAD (critical in patients ≥30 years) and determine whether the SVT burden increases, decreases, or remains stable with exertion 1, 3.
• This serves a dual purpose of evaluating both arrhythmias and ischemia 3.

Laboratory Screening

• Thyroid function tests, electrolytes, complete blood count, and stimulant use testing to exclude secondary precipitants of SVT 1.

Advanced Imaging When Indicated

• Cardiac magnetic resonance imaging is indicated when echocardiography suggests cardiomyopathy, to assess for arrhythmogenic right-ventricular cardiomyopathy or other structural substrates 1.
• Coronary CT angiography or functional stress imaging to rule out CAD in older athletes 1.

Mandatory Specialist Referral

Electrophysiology referral is required in this case:

• Electrophysiology referral is advised when SVT is symptomatic or impairs athletic performance, when initial testing reveals structural heart disease, or when the high burden persists despite medical therapy 1.
• All patients treated for SVT should be referred for a heart rhythm specialist opinion 4.
• Catheter ablation has success rates of approximately 94-98% and is the preferred definitive treatment for recurrent symptomatic SVT 1, 5.

Athletic Participation Restrictions

Temporary restriction from competitive sports is necessary until evaluation is complete:

• When abnormalities are identified (e.g., structural lesions, exercise-induced worsening, high-risk ECG features), immediate cardiology/electrophysiology consultation is required, with consideration of catheter ablation and temporary restriction from competitive sports until definitive treatment is achieved 1.
• International athletic screening guidelines specifically list SVT as an abnormal finding that mandates further investigation, regardless of the athlete's conditioning level 1.

Critical Pitfalls to Avoid

Do not make these common errors:

• SVT should not be dismissed as benign without proper evaluation, as it can be associated with life-threatening conditions including LQTS, WPW, Brugada syndrome, and cardiomyopathies 3.
• The athletic status does not protect against underlying cardiac pathology; SVT is not more common in athletes than in the general population except possibly atrial fibrillation 2.
• Antiarrhythmic drugs should not be initiated for SVT without cardiology consultation, as these medications carry proarrhythmic risk and require careful monitoring 3.

If All Testing Is Normal

Even with normal initial workup, ongoing surveillance is required:

• If all investigations are normal (no structural disease, preserved cardiac function, SVT that suppresses or remains stable with exercise, and absence of high-risk features), continued periodic monitoring is reasonable, though discussion of electrophysiology study and possible ablation remains appropriate 1.
• Regular follow-up with serial cardiac imaging is necessary even when the initial evaluation is normal, in order to monitor for the development of a cardiomyopathy phenotype 2.