ABSTRACT
Masked bifascicular block (MBB) (absent or minimal S in I and VL, high R in Vi and AQRS approximately -60 degrees) is a rare condition. We have found 16 such cases in the last 12 years, thirteen male and three female, mean age 70 +/- 9 years. The conventional electrocardiogram was tabulated and the clinical features and evolution of the patients were followed over 39.1 +/- 32 months. Ten patients required pacemakers, nine because of complete atrioventricular (AV) block or increase in the previous AV block. Seven patients died (follow-up 27.3 +/- 32 months), five from heart failure. This study shows: (1) MBB is a subgroup of patients with a high risk of advanced atrioventricular block; (2) a pacemaker implant does not significantly reduce the high mortality in this group because of the severity of the underlying disease; (3) these results should be evaluated in a larger series of patients in order to confirm our provisional results.
Subject(s)
Bundle-Branch Block/diagnosis , Electrocardiography , Aged , Aged, 80 and over , Female , Humans , Male , Middle AgedABSTRACT
From 81,000 ECGs we collected 83 cases that fulfilled the criteria of Interatrial Conduction Disturbances with Left Atrial Retrograde Activation (IACD-LARA) (P +/- in II, III and VF with P width greater than or equal to 120 msec.). We present the detailed study of 35 cases with surface ECG and VCG and 29 cases with orthogonal ECG leads. The results are then compared against two control groups: with cardiopathy (30 cases) and without cardiopathy (25 cases). The prevalence of IACD-LARA was nearly 1% globally, and 2% among patients with valvular heart disease. The diagnostic criteria for IACD-LARA are: 1) ECG: P +/- in II, III and VF with P greater than or equal to 120 msec. with open angle (usually greater than 90 degrees) between the first and the second part of the P.2) Orthogonal ECG: P +/- in Y lead with a negative mode greater than 40 msec. 3) VCG: More than 50 msec. above the X or Z axis, duration of the P loop greater than or equal to 110 msec., open angle between the two parts of the P loop in both frontal (131.3 degrees +/- 32.3) and right sagital planes (171.2 degrees +/- 15.1), and presence of notches and slurrings in the last part of the P loop.
