Interatrial Block: The Pandemic Remains Poorly Perceived

Abstract

Interatrial block (IAB; P duration >or=110 ms) is a common electrocardiogram abnormality, which in addition to reduced left atrial function predicts atrial fibrillation and other arrhythmias. P terminal force (Ptf) +/- biphasic P in lead V(1)>or= the area of one small square on the grid also indicates left atrial abnormality, particularly left atrial enlargement, which is a strong correlate of IAB. Among 482 consecutively recorded electrocardiograms, IAB and Ptf were strongly and significantly correlated (chi(2)= 68.041; P <or= 0.001).In conclusion, interatrial block exists in pandemic proportions in unselected hospital patients. Because of its pathologic implications it requires widespread attention which, heretofore, has been lacking.

Interatrial blocks. A separate entity from left atrial enlargement: a consensus report

“…The P-wave ECG pattern of interatrial block may appear without associated atrial enlargement 9,28 The prolonged P-wave duration (P-wave duration ≥ 120 milliseconds) may be present in the elderly and also as a consequence of an acute illness as pericarditis or acute myocardial infarction without atrial enlargement. In fact, in these cases, the duration of P wave may be as long as that in LAE, but the P loop does not move so clearly backwards as in a figure 8 shape, which results in a much smaller negative P-wave component in lead V 1 .…”

“…Furthermore, IACT is related not only to an increased P-wave duration but also to a prolonged PR interval. 33,39 We know now that the prevalence of first-degree interatrial block in the general population is very high 9,10 and that this condition has recently been shown to be associated with cardiovascular and allcause mortality. 33 • The presence of third-degree interatrial block is very frequently associated with supraventricular arrhythmias.…”

“…[2][3][4] Since then, there are several reports describing the ECG characteristics of different types of interatrial blocks, and also have been described their clinical implications. [5][6][7][8][9][10][11][12][13][14][15][16] These publications considered that, in spite that the ECG patterns found in left atrial enlargement (LAE) are often significantly influenced by the presence of impaired interatrial conduction, the same as that happens with ventricular enlargement and ventricular blocks, these 2 ECG patterns may appear individually, in spite that the atrial blocks in general and the ECG patterns of interatrial blocks in particular are not described and even mentioned as an ECG pattern in most of books of ECG. [17][18][19][20][21][22] On the contrary, the term atrial abnormalities [23][24][25] has been coined to encompass both the terms LAE and interatrial block.…”

Bayés’ syndrome: the association between interatrial block and supraventricular arrhythmias

“…In the latter, the prevalence was almost 50%. Therefore, IAB is a common entity that is usually unperceived, probably because it is neither suspected nor considered in the differential diagnosis [24].…”

Predictive value of atrial electromechanical delay for atrial fibrillation recurrence

“…These structural changes also lead to a prolongation in P wave duration. P wave duration > 120 ms is considered abnormal [5,6].…”