ST segment criteria for the diagnosis of acute ischemia are affected by the presence of the left bundle branch block
, because of the presented secondary ST changes that occur in this pattern.
Conclusion: The incidence of Intraventricular dyssynchrony is high among patients with heart failure and left bundle branch block
Our findings are corroborated by a systematic review and meta-analysis by Qaddoura et al, in which ECG signs that were good predictors of a negative outcome for in-hospital mortality included S1Q3T3 (OR: 3.38, 95% CI: 2.46-4.66, p<0.001), complete right bundle branch block
(OR: 3.90, 95% CI: 2.46-6.20, p<0.001), T-wave inversion (OR: 1.62, 95% CI: 1.19-2.21, p=0.002), right axis deviation (OR: 3.24, 95% CI: 1.86-5.64, p<0.001), and atrial fibrillation (OR: 1.96, 95% CI: 1.45-2.67, p<0.001)18.
Sgarbossa criteria  is used for electrocardiographic manifestations of ischaemia in the setting of left bundle branch block
. The outcomes observed were heart failure as determined by highest Killip's class,  Arrhythmias, Regional wall motion abnormality (RWMA), Left ventricular ejection fraction (LVEF) and Death.
The resulting segments were divided into 18 different types of beats, namely, normal beat (NOR "N"), atrial premature contraction (APC "A"), fusion of ventricular and normal beat (FVN "F"), left bundle branch block
(LBBB "L"), unclassifiable beat (UN "Q"), premature ventricular contraction (PVC "V"), right bundle branch block
beat (RBBB "R"), ventricular flutter wave (VF "!"), atrial escape beat (AE "e"), fusion of paced and normal beat (FPN "f"), nodal (junctional) premature beat (NP "J"), isolated QRS-like artifact (-), aberrated atrial premature beat (AP "a"), ventricular escape beat (VE "E"), nodal (junctional) escape beat (NE "j"), nonconducted P-wave (blocked APB "x"), paced beat (PACE "/"), and supraventricular premature beat (SP "S").
A repeated 12-lead electrocardiogram revealed sinus tachycardia with incomplete right bundle branch block
. Echocardiogram (performed after resuscitation maneuvers) showed a mildly reduced ejection fraction (44%).
QRSs show right bundle branch block
with a QRS duration of 0.13 seconds, broad S waves in leads I, II, aVL, V5, V6, broad R waves in lead aVR, and broad R' waves in lead V1.
Other conduction abnormalities include right bundle branch block
, sinus bradycardia, and prolonged QT interval.
Table 1: ECG findings of acute hair dye poisoning Manifestation Number (%) Normal 5 (10) ST-T change 21 (42) Bundle branch block
4 (8) AV Block 7 (14) Bundle branch with AV block 2 (4) Arterial fibrillation 3 (6) Arterial flutter 2 (4) Ventricular tachycardia 1 (2) APC 1 (2) EAT 1 (2) Ventricular ectopic 1 (2) Supraventricular tachycardia 1 (2) VPC 1 (2) Total 50 (100) ST-T, ST and T wave; AV, atrioventricular; APC, atrial premature complexes; EAT, ectopic atrial tachycardia; VPC, ventricular premature complexes; ECG, electrocardiographic.
(9) Sudden increases in right-sided pressure can lead to transient right bundle branch block
, which may result in complete heart block in the setting of baseline left bundle branch block
A wide complex tachycardia has a QRS duration >120 ms and may be caused by one of the following mechanisms: (i) ventricular tachycardia, which must be the default diagnosis in any patient with a wide complex tachycardia; (ii) supraventricular tachycardia with a right or left bundle branch block
or an intraventricular conduction abnormality; (iii) pre-excited tachycardia (Wolff-Parkinson-White syndrome) over an accessory pathway; and (iv) pacemaker tachycardia.
Verapamil also reduced the frequency of chest blow induced bundle branch block
(BBB), 0 of 7 verapamil strikes compared to 9 of 16 (56%) placebo strikes (p = 0.03).
Electrocardiogram showed normal sinus rhythm with a right bundle branch block
The ECG findings revealed supraventricular heart rhythm, with left bundle branch block
. The ultrasound revealed mild hepatosplenomegaly with right inguinal lymph node enlargement with an abscess in the left inguinal region.
New analyses from a large study conducted in 2009, called MADIT-CRT, presented at the American College of Cardiology's 2014 Scientific Sessions in March, showed that CRT-D in patients with asymptomatic or mildly symptomatic heart failure (NYHA I/II) significantly reduces the risk of death or complications from heart failure when the patient has left bundle branch block
, a condition that causes the left ventricle to contract later than the right ventricle.