Age-related changes in P wave morphology in healthy subjects

Abstract

BackgroundWe have previously documented significant differences in orthogonal P wave morphology between patients with and without paroxysmal atrial fibrillation (PAF). However, there exists little data concerning normal P wave morphology. This study was aimed at exploring orthogonal P wave morphology and its variations in healthy subjects.Methods120 healthy volunteers were included, evenly distributed in decades from 20–80 years of age; 60 men (age 50+/-17) and 60 women (50+/-16). Six-minute long 12-lead ECG registrations were acquired and transformed into orthogonal leads. Using a previously described P wave triggered P wave signal averaging method we were able to compare similarities and differences in P wave morphologies.ResultsOrthogonal P wave morphology in healthy individuals was predominately positive in Leads X and Y. In Lead Z, one third had negative morphology and two-thirds a biphasic one with a transition from negative to positive. The latter P wave morphology type was significantly more common after the age of 50 (P < 0.01). P wave duration (PWD) increased with age being slightly longer in subjects older than 50 (121+/-13 ms vs. 128+/-12 ms, P < 0.005). Minimal intraindividual variation of P wave morphology was observed.ConclusionChanges of signal averaged orthogonal P wave morphology (biphasic signal in Lead Z), earlier reported in PAF patients, are common in healthy subjects and appear predominantly after the age of 50. Subtle age-related prolongation of PWD is unlikely to be sufficient as a sole explanation of this finding that is thought to represent interatrial conduction disturbances. To serve as future reference, P wave morphology parameters of the healthy subjects are provided.

Abnormal atrial activation is common in patients with arrhythmogenic right ventricular cardiomyopathy

“…Forty ethnically-, age-and gender-matched, healthy subjects were selected for a 1:1 case-control comparison from a database of healthy volunteers recruited in Southern Sweden. 12 The study was approved by the local ethics committees and complied with the Declaration of Helsinki. All subjects gave informed consent to participation.…”

“…either positive or biphasic in orthogonal lead Z and positive in leads X and Y, are the most common morphological types that are equally common in healthy population. While Type 1 is more common in adolescents and young adults, 12,22 Type 2 is the predominant morphology in elderly, 12 and commonly observed in patients with paroxysmal atrial fibrillation. 16,23 Type 3 (biphasic P wave in inferior leads) corresponding to the advanced interatrial block with retrograde left atrial activation has not been observed in our cohort of healthy controls, but was present in one ARVC patient who did not have any structural right ventricular abnormality by echo or MRI.…”

Interatrial conduction can be accurately determined using standard 12-lead electrocardiography: Validation of P-wave morphology using electroanatomic mapping in man

“…25,26 Unfiltered, signal-averaged P waves were analyzed to determine P wave morphology. 19,20,24,25 Following high-pass (0.5 Hz) and bandstop (50 Hz) filtering the QRS complexes were 4 automatically identified and grouped according to similarity (a cross-correlation coefficient, ρ > 0.9). P waves were extracted using 250 ms wide signal windows preceding each QRS complex.…”

“…The method used is described in detail elsewhere. 19,20,25 The morphology was subsequently classified into one of three predefined classes ( …”

“…[19][20][21] It was recently suggested that the three different P wave morphology classes that have been identified (Figure 1), [19][20][21] arise from differences in interatrial conduction. 20 If confirmed, this 2 may vastly improve clinical diagnostic abilities in the case of atrial arrhythmia.…”