What does an ECG (Electrocardiogram) showing sinus rhythm with a borderline short PR (P-R) interval and an RSR' pattern in leads V1 or V2, indicating right Ventricular Conduction Delay (VCD) or Right Ventricular Hypertrophy (RVH), mean?

ECG Interpretation: Sinus Rhythm with Borderline Short PR Interval and RSR' Pattern in V1-V2

What This Means in Simple Terms

Your heart rhythm is normal (sinus rhythm), but the electrical signal travels slightly faster than usual through part of your heart (borderline short PR interval), and there's a specific pattern in the electrical recording (RSR' in V1-V2) that could be completely normal or might indicate your right heart chamber is either slightly enlarged or has a minor electrical conduction variation. 1, 2

Breaking Down Each Finding

Sinus Rhythm

• This is completely normal - your heart's natural pacemaker is working properly and controlling your heartbeat 1
• No concern here whatsoever

Borderline Short PR Interval

• The PR interval measures how long it takes for the electrical signal to travel from the upper chambers (atria) to the lower chambers (ventricles) of your heart 1
• "Borderline short" means it's slightly faster than average but not definitively abnormal - typically between 100-120 milliseconds when normal is 120-200 milliseconds 1
• In most cases, this is a benign finding, especially if you have no symptoms 3
• Rarely, a truly short PR interval (less than 120 ms) combined with other findings could indicate an extra electrical pathway in the heart, but "borderline" short typically doesn't warrant concern 4

RSR' Pattern in V1 or V2

This is the most important finding to understand, as it has several possible meanings:

Most Likely Explanation: Normal Variant

• In many people, especially children, young adults, and athletes, this pattern is completely normal and requires no treatment or follow-up 1, 2
• The American College of Cardiology specifically states that an RSR' pattern with normal QRS duration (the width of the electrical signal) is considered a normal variant 1, 2
• If your QRS duration is less than 110 milliseconds, this is almost certainly a benign finding 2, 5

Other Possibilities Depending on QRS Duration:

Incomplete Right Bundle Branch Block (RBBB):

• If the QRS duration is 110-119 milliseconds, this represents incomplete RBBB 1, 2
• This is generally benign in asymptomatic people and often requires only routine monitoring 5
• The right bundle branch is one of the electrical "highways" in your heart; incomplete block means there's a slight delay but not a complete interruption 1

Complete Right Bundle Branch Block:

• If QRS duration is ≥120 milliseconds, this represents complete RBBB 1, 2
• This warrants evaluation for underlying structural heart disease, particularly if you have symptoms like shortness of breath, chest pain, or palpitations 5

Right Ventricular Conduction Delay (VCD) or Right Ventricular Hypertrophy (RVH):

• The RSR' pattern can sometimes indicate the right ventricle (pumping chamber) is either thickened (hypertrophy) or has delayed electrical conduction 1
• RVH is harder to detect on ECG than left ventricular hypertrophy because the left ventricle normally dominates the electrical signal 1
• Common causes of RVH include lung disease, congenital heart conditions, or conditions that increase pressure in the lungs 1
• Additional ECG features would typically be present if true RVH exists, such as right axis deviation or specific voltage criteria 1

What You Should Do

If You Have NO Symptoms:

• Most likely, this requires no specific treatment or further testing 2, 5
• Routine follow-up with your doctor is appropriate 5

If You Have Symptoms (shortness of breath, chest pain, palpitations, fainting, dizziness):

• You need further evaluation, which may include an echocardiogram (ultrasound of the heart) to look at heart structure and function 5
• Your doctor should assess for underlying heart or lung conditions 1, 5

Key Factors That Determine Next Steps:

• Your age - this pattern is more commonly normal in younger people 1
• QRS duration - the single most important measurement to determine if this is normal or needs evaluation 2, 5
• Presence of symptoms - any cardiac symptoms warrant investigation 5
• Family history - history of sudden cardiac death or inherited heart conditions requires more careful evaluation 5

Important Caveats

• The term "borderline" means your doctor is being appropriately cautious but doesn't necessarily indicate disease 1
• An RSR' pattern can occasionally be the first sign of rare conditions like Brugada syndrome (a genetic arrhythmia disorder), but this would typically show additional specific features on the ECG 5, 6
• Proper lead placement matters - sometimes this pattern can appear if the ECG leads are placed slightly higher than standard position 1

Bottom Line

In the vast majority of cases, especially in young, healthy, asymptomatic individuals, this combination of findings represents normal variants that require no treatment. 1, 2 The key is ensuring your QRS duration is normal (less than 110 ms in adults) and that you have no cardiac symptoms or concerning family history. 2, 5 Your doctor may simply want to document this as your baseline normal pattern for future reference.