Disease relevance of Bundle-Branch Block

• Verapamil-sensitive, idiopathic left ventricular tachycardia (ILVT) with right bundle branch block configuration and left-axis deviation has been suggested to originate from the left posterior fascicle [1].
• Acute myocardial infarction and complete bundle branch block at hospital admission: clinical characteristics and outcome in the thrombolytic era. GUSTO-I Investigators. Global Utilization of Streptokinase and t-PA [tissue-type plasminogen activator] for Occluded Coronary Arteries [2].
• These patients included a 67 year old man with complete heart block of 13 years' duration, and his son, who had left bundle branch block and chronic generalized cardiomyopathy [3].
• Patients with documented history of infarction, coronary artery bypass grafting, pathologic Q waves on the electrocardiogram, left bundle branch block or nonischemic cardiomyopathy were not included [4].
• Women were younger, more likely to be black, had a higher prevalence of nonischemic etiology, higher right and left ventricular ejection fraction, higher heart rate, greater cardiothoracic ratio, higher prevalence of left bundle branch block, lower prevalence of atrial fibrillation, and lower plasma norepinephrine level [5].

High impact information on Bundle-Branch Block

• Disopyramide and bundle-branch block [6].
• BACKGROUND: The prognostic value of tomographic myocardial perfusion imaging with dipyridamole or adenosine in patients with left bundle-branch block has not been established [7].
• Patients with bundle-branch block had lower ejection fractions, higher peak creatine phosphokinase levels (P < .0001), and more diseased vessels (P < .019) [8].
• Despite the presence of left bundle branch block, DDD pacing reduced LVOT obstruction significantly in 15 patients (LVOT gradient, baseline 89 +/- 36 mm Hg versus 18 +/- 26 mm Hg at follow-up, P < .0001) [9].
• Regional myocardial perfusion and glucose metabolism in experimental left bundle branch block [10].

Chemical compound and disease context of Bundle-Branch Block

• Effects of isoproterenol on bradycardia-dependent intra-His and left bundle branch blocks [11].
• The experience with bundle branch block at the USAF School of Aerospace Medicine was reviewed [12].
• A new approach to the assessment of tomographic thallium-201 scintigraphy in patients with left bundle branch block [13].
• BACKGROUND: Reentry is the operative mechanism of idiopathic left ventricular tachycardia, with a QRS complex of right bundle branch block and superior axis that is responsive to verapamil but not adenosine [14].
• Contrasting effects of verapamil and procainamide on rate-dependent bundle branch block: pharmacologic evidence for the role of depressed sodium channel responses [15].

Biological context of Bundle-Branch Block

• Biventricular pacing combined with cardiac surgery for patients with cardiomyopathy and complete left bundle branch block may produce beneficial effects on LV function [16].
• Global and regional myocardial oxygen consumption and blood flow in severe cardiomyopathy with left bundle branch block [17].
• Regional and global myocardial blood flow and coronary vascular resistance were determined in patients with idiopathic-dilated cardiomyopathy and left bundle branch block before and during cardiac resynchronization therapy (CRT) using oxygen-15 water positron emission tomography [18].
• Right bundle branch block: a source of error in the Doppler assessment of right ventricular pressure in patients with a ventricular septal defect [19].
• We identified 12 affected individuals (right bundle-branch block, > or =1-mm STE) with an autosomal dominant inheritance pattern characterized by incomplete penetrance that appeared to be dependent on age and sex [20].

Anatomical context of Bundle-Branch Block

• In conclusion, septal and anterior thallium-201 SPECT defects are common in patients with left bundle branch block without coronary artery disease, resulting in low specificity for left anterior descending artery disease [13].
• He was found to have an asymmetric crying face, preaxial polydactyly on the right, a small midmuscular ventricular septal defect with an incomplete right bundle branch block on echocardiogram, a small cleft in T3, and incomplete development of the left half of the sacrum [21].
• Cardiac electrical instability after operation was significantly related to larger operative body size, higher postoperative end diastolic diameter of the right ventricle, larger size of the ventricular septal defect, coexistence of postoperative right bundle branch block and left anterior hemiblock [22].
• In this report we describe a patient with congenital tricuspid valve stenosis, ostium secundum atrial septal defect, and electrocardiographic left anterior fascicular block, who presented with paradoxical emboli [23].
• A 44-year-old man developed intermittent left bundle branch block followed by complete heart block 18 months after aortic valve replacement, and aortic insufficiency and hemolytic anemia 5 years postoperatively [24].

Gene context of Bundle-Branch Block

• Brugada syndrome, an autosomal dominantly inherited form of ventricular fibrillation characterized by ST-segment elevation in leads V1-V3 and right bundle-branch block on surface electrocardiogram, is caused by mutations in the cardiac sodium channel gene SCN5A [25].
• METHODS: The North American population with acute MI and bundle branch block enrolled in the Global Utilization of Streptokinase and t-PA [tissue-type plasminogen activator] for Occluded Coronary Arteries (GUSTO-I) trial was matched by age and Killip class with an equal number of GUSTO-I patients without conduction defects [2].
• CONCLUSIONS: Our data show that (1) in mice, a continuity exists between the common bundle and the septum, and (2) Cx40 deficiency results in right bundle-branch block and impaired left bundle-branch conduction [26].
• The RPEP/RVET could not be used to assess PA pressure in six patients with congestive cardiomyopathy nor in 18 patients with complete right bundle branch block (CRBBB) [27].
• Magnetic measurement of S-T and T-Q segment shifts in humans. Part I: Early repolarization and left bundle branch block [28].

Analytical, diagnostic and therapeutic context of Bundle-Branch Block

• We sought to assess the comparative diagnostic accuracy of adenosine versus exercise in conjunction with thallium-201 scintigraphy for the detection and localization of coronary artery disease in patients with left bundle branch block on the rest electrocardiogram (ECG) [29].
• PATIENTS AND METHODS: Three hundred eighty-seven patients [230 men and 157 women, mean (+/- SD) age, 64 +/- 9 years] with complete left bundle branch block on the resting electrocardiogram underwent dobutamine (n = 217) or dipyridamole (n = 170) stress echocardiography to evaluate suspected or known coronary artery disease [30].
• In case of a persistent bundle branch block associated with elevated CK MB isoenzymes, new left ventricular wall motion disturbances indicating a peri-operative myocardial injury are easily detected by transoesophageal echocardiography [31].
• Relation between exercise-induced myocardial ischemia as assessed by nitrogen-13 ammonia positron emission tomography and QT interval behavior in patients with right bundle branch block [32].
• PATIENTS: 31 patients with dilated cardiomyopathy and without bundle branch block were included in a retrospective study and 16 in a prospective study [33].

References