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Risk for atrial fibrillation in patients with hypertrophic cardiomyopathy assessed by signal averaged P wave duration
F Cecchi1, A Montereggi, I Olivotto
1Cardiologia di S Luca, Ospedale di Careggi, Florence, Italy.
Insights
In hypertrophic cardiomyopathy (HCM), prolonged P wave duration on electrocardiography can predict atrial fibrillation risk. This non-invasive measure helps identify patients needing closer monitoring for electrical instability.
Area of Science:
- Cardiology
- Electrophysiology
Background:
- Hypertrophic cardiomyopathy (HCM) is associated with an increased risk of atrial fibrillation (AF).
- Identifying patients with HCM at risk for AF is crucial for timely intervention and management.
Purpose of the Study:
- To investigate the relationship between P wave duration during sinus rhythm and the incidence of AF in patients with HCM.
- To evaluate the utility of signal-averaged electrocardiography (SAECG) in predicting AF in this population.
Main Methods:
- A high-resolution signal-averaged electrocardiography (SAECG) was performed on 110 patients with HCM.
- Filtered P wave duration was manually measured from an average of 300 beats per patient during sinus rhythm.
- Patients were followed for the occurrence of clinical AF episodes.
Main Results:
- 16% of patients developed clinical AF during follow-up.
- Patients who developed AF had significantly longer P wave durations (150 ms) compared to those who did not (126 ms).
- A P wave duration of ≥140 ms demonstrated 56% sensitivity and 83% specificity for predicting AF. Combining this with left atrial enlargement improved specificity to 93%.
Conclusions:
- P wave duration measured by SAECG is a valuable non-invasive tool for identifying HCM patients at risk of developing AF.
- This method can help detect electrical instability and guide proactive management strategies in HCM patients.
Objective:
To assess the relation between P wave duration and the occurrence of atrial fibrillation in hypertrophic cardiomyopathy (HCM).
Design:
High resolution signal averaged electrocardiography was used in 110 patients with HCM to determine whether patients at risk for paroxysmal atrial fibrillation could be detected during sinus rhythm by measuring P wave duration. Filtered P wave duration was measured manually, over an average of 300 beats per patient.
Results:
During follow up, 18 patients (16%) had at least one one clinical episode of paroxysmal atrial fibrillation, including four patients whose initial episode followed the signal averaged electrocardiogram. The 18 patients with overt atrial fibrillation had greater P wave duration than the 69 patients who did not develop atrial fibrillation: 150 (SD 20) v 126 (14) ms; P < 0.001. Another 23 patients without clinically evident atrial fibrillation had prolonged bursts of the arrhythmia on Holter recording, and showed a P wave duration (138 (15) ms) intermediate between patients with and without clinical atrial fibrillation. In assessing risk for atrial fibrillation, P wave duration > or = 140 ms was associated with sensitivity, specificity, and positive predictive accuracy values of 56%, 83%, and 66%. Multivariate analysis showed that duration of the P wave was the only independent variable associated with occurrence of atrial fibrillation; if P wave duration > or = 140 ms was combined with left atrial enlargement > 40 mm, the specificity and positive predictive accuracy for atrial fibrillation increased to 93% and 78%.
Conclusions:
Measurement of P wave duration in sinus rhythm by high resolution signal averaged electrocardiography may be a useful non-invasive clinical tool for identifying patients with HCM likely to develop electrical instability and atrial fibrillation.