Bilateral Bundle Branch Block Research Articles

Bilateral Bundle Branch Block.

Left bundle branch block (LBBB) and right bundle branch block (RBBB) are classic manifestations of bundle branch conduction disorders. However, a third form that is uncommon and underrecognized may exist that has features and pathophysiology of both: bilateral bundle branch block (BBBB). This unusual form of bundle branch block exhibits an RBBB pattern in lead V1 (terminal R wave) and an LBBB pattern in leads I and aVL (absence of S wave). This unique conduction disorder may confer an increased risk of adverse cardiovascular events. BBBB patients may be a subset of patients that respond well to cardiac resynchronization therapy.

POST MYOCARDIAL INFARCTION ARRHYTHMIAS IN 1 24 HOURS

BACKGROUND: Post myocardial infarction arrhythmias can very commonly lead to death. Hence we studied the various arrhythmias arisingwithintherst24hours ofmyocardialinfarction. METHODS: Myocardial infarction was conrmed with detailed history, clinical examination, laboratory investigations, and 12 lead electrocardiogram. 50 patients who presented within 1 hour of onset ofsymptoms were included in study. Patients' cardiac rhythm was monitored for at least 72 hours in intensive coronary care unit. RESULTS:IncidenceofvariousTachyarrhythmiaswere: 1. Ventriculartachycardia (8%), 2. AtrialFibrillation(4%), 3. Supraventriculartachycardia (2%). 4. Ventricularbrillationwas notobserved. CONCLUSION:Arrhythmias carrying very high mortality were complete heart block, bilateral bundle branch block and right bundle branch block. Arrhythmiaswithanteriorwallinfarctioncarriedbadprognosiswhile arrhythmiaswithinferiorwallinfarctionhadgoodprognosis.

Bilateral Bundle Branch Block.

Left bundle branch block (LBBB) and right bundle branch block (RBBB) are classic manifestations of bundle branch conduction disorders. However, a third form that is uncommon and underrecognized may exist that has features and pathophysiology of both: bilateral bundle branch block (BBBB). This unusual form of bundle branch block exhibits an RBBB pattern in lead V1 (terminal R wave) and an LBBB pattern in leads I and aVL (absence of S wave). This unique conduction disorder may confer an increased risk of adverse cardiovascular events. BBBB patients may be a subset of patients that respond well to cardiac resynchronization therapy.

Results of early laparoscopic cholecystechtomy in patients with acute calculous cholecystitis and concomitant ischemic heart disease

The aim — to evaluate the results of early laparoscopic cholecystectomy (LC) in patients with acute calculous cholecystitis (АСС) and concomitant ischemic heart disease.Materials and methods. The study included 107 patients with ACC: 56 (47.7 %) women and 51 (52.3 %) men aged 55 to 82 years old, on average 70.2 ± 0.6 years, treated at the surgical department. All patients were hospitalized within 29.9 ± 1.4 hours. Among all patients with angina pectoris 93 (86.9 %) had stable variant, 14 (13.1 %) — unstable, 6 (6.5 %) patients have had I class of stable angina pectoris, II class have had 45 (48.4 %), III class — 31 (33.3 %), IV class — 11 (11.8 %) of patients. According to NYHA classification, functional class of chronic heart failure (CH) had been diagnosed in 8 (7.5 %) patients, II class — in 59 (55.1 %), III class — in 33 (30.8 %), IV class — in 7 (6.5 %) of cases. 29 (27.1 %) patients have had atrial fibrillation, including permanent form in 19 (65.5 %), paroxysmal form — in 10 (34.5 %) of patients. ESV had been reported in 5 (4.7 %) patients. According to the classification of TG13, the severity of ACC variates: I grade in 37 (34.6 %) patients, II grade — in 41 (38.3 %), and grade III — in 29 (27.1 %) of patients. Anticoagulant and antiplatelet therapy before surgery was given to 95 (88.8 %) of patients. The frequency of catarrhal, phlegmonous and gangrenous forms of LC was 46 (43.0 %), 29 (27.1 %), 32 (29.9 %), respectively. In 47 (43.9 %) of patients there was a paracystic infiltrate, in 14 (13.1 %) — paravesical abscess, in 12 (11.2 %) — local peritonitis. LC (with the creation of carboxyperitoneum 12 — 15 mm Hg) is performed on average 41.1 ± 1.3 hours from the onset of the disease. The method of choice for anesthesia was total intravenous anesthesia (TIVA) with trachea intubation and artificial lung ventilation. The study points were cardiac events in the intraoperative and early postoperative periods.Results and discussion. ECG­signs of intraoperative myocardial ischemia appeared in 23 (21.5 %) patients with duration ranged from 10 up to 25 min, on average 14.8 ± 0.7 min, systolic blood pressure (SBP) < 70 mm Hg decreasing for 5 — 15 min (on average 7.7 ± 0.4 min) registered in 31 (29.0 %) patients; decreasing diastolic blood pressure < 50 mm Hg — in 12 (11.2 %) patients, lasting from 5 to 15 min, on average 8.1 ± 0.4 min. Episodes of reduced saturation level occured in 50 (46.3 %) patients. Bilateral bundle branch block occurred in 9 (8.4 %) patients and atrial fibrillation paroxysms occurred in 9 (8.4 %) patients. Elevated tissue bleeding was observed in 18 (16.8 %) of patients. Stepping up in the NYHA class in the postoperative period occurred in 13 (12.1 %) patients. In this case, the intensification of heart failure occurred in 9 patients from HF II to HF III, and in 4 patients from HF III to HF IV. The deepening of HF correlated with a hemoglobin decreasing < 100 g/L (r = 0.704), episodes of decreasing SBP < 70 mm Hg (R = 0.569), decreased saturation (< 90 %) (r = 0.547), ischemia during anesthesia (r = 0.363), duration of operation (r = 0.495), and negatively correlated with MET (r = –0.436). The ratio of chances for HF deepening in patients with destructive cholecystitis to non­destructive cholecystitis is 11.02 (95 % DM: 1.4 — 88.2). Myocardial infarction (MI) developed in 6 (5.6 %) patients (Q­infarction — in 2, and non Q­infarction — in 4). The occurrence of MI correlated significantly with the intensification of the heart failure (r = 0.438), hypercoagulation before surgery (r = 0.333) and a hemoglobin decreasing < 100 g/L during the operation (r = 0.311).Conclusions. In patients with ACC and concomitant IHD, myocardial ischemia was observed in 21.5 % of patients with early LC. Blood pressure lowering: systolic (< 70 mm Hg) in 29.0 %, diastolic (< 50 mm Hg). Besides that, 11.2 % of patients have had reduction of saturation level (< 90 %) in 46.3 %, new episodes of cardiac arrhythmia in 16.8 %, increased bleeding in 16.8 %. Intensification of HF and MI in the postoperative period occurs in 12.1 % and 5.6 % of patients, respectively. Complications for the cardiovascular system correlate with the form of ACC and its severity class (TG13), NYHA class, FC for angina pectoris, MET level, changes in the hemostatic system (hyper­ and hypocoagulation), and preliminary anticoagulant therapy.

Left accessory pathway with decremental conduction and bilateral bundle branch block and slow pathway: an unusual combination

Left accessory pathway with decremental conduction and bilateral bundle branch block and slow pathway: an unusual combination

Bilateral bundle branch block during treatment with amitriptyline

A 57 year-old man treated with amitriptyline was admitted because of several episodes of syncope. In ECG, the incomplete left bundle branch block was masked by the complete right bundle branch block and left anterior fascicular block.

A07-1 Beat-to-beat alternating bilateral bundle branch block: Clinical, electrocardiographic and electrophysiological characteristics

A07-1 Beat-to-beat alternating bilateral bundle branch block: Clinical, electrocardiographic and electrophysiological characteristics

A07-1 Beat-to-beat alternating bilateral bundle branch block: Clinical, electrocardiographic and electrophysiological characteristics

A07-1 Beat-to-beat alternating bilateral bundle branch block: Clinical, electrocardiographic and electrophysiological characteristics

Repetitive supernormal conduction in the right bundle branch in high degree bilateral bundle branch block

Electrocardiograms were taken from a 67-year-old woman with high-degree atrioventricular block in which ventricular escape beats of right bundle branch block pattern occurred, accompanying occasional ventricular capture beats. Only when a sinus P wave occurred 0.60 s after the preceding escape beat, it was followed by a capture beat of left bundle branch block pattern with the RP interval of 0.60 s and the PR interval of 0.19 s. Similar left bundle branch block with left axis deviation pattern had been shown in the electrocardiogram taken 2 years before. Such RP and PR intervals in capture beats were invariable. These suggest that capture beats occurred as a result of supernormal conduction in the right bundle branch, which denies the possibility of ventricular extrasystoles. Such capture beats with the above RP and PR intervals were observed repeatedly.

Recurrent symptomatic bilateral bundle branch block in a 74-year-old patient with a prosthetic aortic valve: A description of a case and review of the literature

This report concerns a 74-year-old patient who had undergone aortic valve replacement 11 years earlier. On admission, the patient complained of shortness of breath when climbing two flights of stairs; there was no history of dizziness, fainting or sensations of arrhythmias. An ECG at rest showed first-degree atrioventricular (A-V) block together with left bundle branch block (LBBB). On bicycle ergometry, there was a fall in blood pressure and in heart rate due to a second-degree (2:1) A-V block along with the LBBB. After termination of exercise, the PR interval increased further from 0.24 s to >0.3 s, together with right bundle branch block (RBBB) and 1:1 A-V conduction instead of LBBB. Finally, at a constant atrial rate of 98/min, the RBBB disappeared, LBBB recurred, again with 2:1 A-V conduction. The diagnosis was bilateral BBB together with first degree A-V block at rest and higher-degree A-V block on effort. The patient underwent pacemaker implantation and was discharged shortly thereafter free of symptoms.

Electrocardiographic and Clinical Predictors of Torsades de Pointes Induced by Almokalant Infusion in Patients with Chronic Atrial Fibrillation or Flutter: A Prospective Study

The aim of this study was to identify predictors of torsades de pointes (TdP) in patients with atrial fibrillation (AF) or flutter exposed to the Class III antiarrhythmic drug almokalant. TdP can be caused by drugs that prolong myocardial repolarization. One hundred patients received almokalant infusion during AF (infusion 1) and 62 of the patients during sinus rhythm (SR) on the following day (infusion 2). Thirty-two patients converted to SR. Six patients developed TdP. During AF, T wave alternans was more common prior to infusion (baseline) in patients developing TdP (50% vs 4%, P < 0.01). After 30 minutes of infusion 1, the TdP patients exhibited a longer QT interval (493 +/- 114 vs 443 +/- 54 ms [mean +/- SD], P < 0.01), a larger precordial QT dispersion (50 +/- 74 vs 27 +/- 26 ms, P < 0.05), and a lower T wave amplitude (0.12 +/- 0.21 vs 0.24 +/- 0.16 mV, P < 0.01). After 30 minutes of infusion 2, they exhibited a longer QT interval (672 +/- 26 vs 489 +/- 74 ms, P < 0.001), a larger QT dispersion in precordial (82 +/- 7 vs 54 +/- 52 ms, P < 0.01) and extremity leads (163 +/- 0 vs 40 +/- 34 ms, P < 0.001), and T wave alternans was more common (100% vs 0%, P < 0.001). Risk factors for development of TdP were at baseline: female gender, ventricular extrasystoles, and treatment with diuretics; and, after 30 minutes of infusion: sequential bilateral bundle branch block, ventricular extrasystoles in bigeminy, and a biphasic T wave. Patients developing TdP exhibited early during almokalant infusion a pronounced QT prolongation, increased QT dispersion, and marked morphological T wave changes.

Association of reduced PR-AC interval with ventricular early potentials in dilated cardiomyopathy

We studied 31 patients with dilated cardiomyopathy, correlating mitral valve cusp motion with the continuous wave Doppler signal of mitral regurgitation and the signal averaged electrocardiogram (ECG). Sixteen patients had a B point (early partial closure) on the mitral echogram and 15 did not. Fifteen normal cases were used as controls. The duration of ventricular early potentials (< 40 μV) was measured on the signal averaged ECG of the QRS complex. The PR interval was increased in patients with a B point (190 (33) ms vs. 145 (16) ms in normal, P < 0.01) and PR-AC interval was reduced (25 (71) ms vs. 65 (11) ms in normal, P < 0.05). The B point itself was effectively synchronous with the onset of low velocity early systolic mitral regurgitation, and followed the Q wave of the succeeding beat by 20 ms or less. Early low velocity on mitral regurgitation was not present in patients without a B point. The duration of early potentials was greatly increased in patients with a B point (43 (26) ms) compared both to those without (17 (20) ms, P < 0.01) and to normals (12 (7) ms, P < 0.01) and their duration correlated with B-C interval ( r = 0.6, P < 0.02). We conclude that a B point on the mitral echogram in patients with left ventricular disease is due to early systolic low velocity mitral regurgitation which itself results from an abnormal pattern of left ventricular activation, probably bilateral bundle branch block. Once established, this low velocity jet delays complete mitral valve closure.

Nature of ventricular activation in patients with dilated cardiomyopathy: evidence for bilateral bundle branch block.

To investigate the nature of ventricular activation and its relation with mechanical events in patients with dilated cardiomyopathy. Retrospective and prospective study with 12 lead electrocardiograms, signal averaged electrocardiograms, and M mode and Doppler echocardiograms. Tertiary cardiac referral centre. 77 patients (mean (SD) age 59(13)) with dilated cardiomyopathy, four after aortic valve replacement and three after coronary bypass surgery, and six patients with a normal sized left ventricle and complete right bundle branch block were studied. 15 normal subjects (age 45(20)) were used as controls. In patients with dilated cardiomyopathy, QRS duration was longer (127(25) ms v 90(10), P < 0.05) than normal and was normally distributed (r = 0.991, P < 0.01) on a normal probability plot. 20 had classic left bundle branch block, 29 intraventricular conduction delay, four right bundle branch block, and one bifascicular block. The PR interval was prolonged (185(30) ms v 150(15), P < 0.05). Electromechanical delay, Q to the onset of thickening of the interventricular septum as seen on the transverse M mode echocardiogram, was 75(15) ms in controls, but reduced to 43(15) ms in the patients (P < 0.01). Q to the onset of mitral regurgitation was also short (50(15)) ms, and correlated inversely with PR interval (r = -0.67, n = 73, P < 0.01). Early potentials (< 40 microV) were recorded on the signal averaged electrocardiogram in 33 representative patients and in all controls. Their overall duration was 30(12) ms in the patients, much longer than normal (12(7), P < 0.01)). Early potential time correlated positively with PR interval (r = 0.75, P < 0.01) and QRS duration (r = 0.60, P < 0.01) on a 12 lead electrocardiogram, and negatively with apparent electromechanical delay (r = -0.71, P < 0.01, n = 33), but not with true electromechanical delay (73(15)ms) or true PR interval (163(30)ms), calculated by correcting apparent values for early potential. The onset of left ventricular free wall motion was delayed with respect to the septum beyond 95% of the upper normal limit in all the patients with classic left bundle branch block and intraventricular conduction defect. Motion in the right ventricular free wall was delayed in 13 of 20 patients with left bundle branch block and 24 of 29 with intraventricular conduction defect by 65(20) ms, similar to that (75(10) ms) in patients with right bundle branch block. In most patients with dilated cardiomyopathy and an electrocardiographic pattern of left bundle branch block or intraventricular block, the onset of mechanical systole is strikingly and symmetrically delayed in both ventricles, compatible with bilateral bundle branch block. Complete atrioventricular block does not occur. The ventricle is activated through the upper septum and this activation is detectable only by signal averaged electrocardiography. The anatomical substrates for this abnormal activation could be the high connections described by Mahaim and Winston.

Sequential Bilateral Bundle Branch Block During Dofetilide, A New Class III Antiarrhythmic Agent, In a Patient with Atrial Fibrillation

The mechanism of wide QRS complex tachycardias during dofetilide infusion was studied in a patient with atrial fibrillation. Endocardial recordings from the intraventricular conduction system showed that dofetilide caused "classic" aberrant conduction (Ashman phenomenon, typical QRS morphology) at high prematurity ratios (preceding interval = 1.78 x coupling interval--290), thus mimicking ventricular ectopy. In addition, there was frequent sequential bilateral bundle branch block, caused by a significant difference in preceding bundle-to-bundle intervals (mean difference +/- 1 SD: 74 +/- 26 msec). The present findings may prove helpful in the clinical assessment of wide QRS complex rhythms after dofetilide and possibly other "pure" Class III antiarrhythmics.

Electrocardiographic criteria for the diagnosis of the left septal fascicular block and its frequency among primarily elderly hospitalized patients

Characteristic electrocardiographic findings of the left septal fascicular block consist of a prominent anterior QRS force. Therefore, the following criteria were proposed for the diagnosis of left septal fascicular block, based on the normal limits of the R and S waves and R/S of V1 and V2. (1) Right ventricular hypertrophy, complete right bundle branch block, preexcitation (Type A), high posterior infarction, hypertrophic cardiomyopathy and abnormality of the thorax or intrathoracic tissues which might cause marked counterclockwise rotation around the longitudinal axis of the heart, should be excluded. (2) One of the following two criteria should be satisfied. (i) R/Sv1 greater than 2, and Rv1 greater than or equal to 5 mm, (ii) R/Sv2 greater than 2, and Rv2 greater than or equal to 15 mm, or Sv2 less than 5 mm. The frequency of left septal fascicular block diagnosed by these criteria was 3.5% among all patients of a hospital mainly consisting of elderly patients. This frequency was less than that of the left anterior fascicular block or complete right bundle branch block, but it was higher than that of the complete left bundle branch block or bilateral bundle branch block.

Guide Wire as a Cause of Complete Heart Block in Patients with Preexisting Left Bundle Branch Block

Catheter-induced arrhythmia is a well-recognized complication encountered during insertion of conventional of flow-directed balloon-tipped catheters. We describe a case of iatrogenically induced asystole due to the production of bilateral bundle branch block and the absence of an escape rhythm in a patient with a preexisting LBBB

Bradyarrhythmias, Abnormalities of Conduction, and Indications for Pacing in Acute Myocardial Infarction

Bradyarrhythmias and conduction disturbances are not infrequently observed in association with acute MI. The sinus node artery is supplied by the right coronary circulation only slightly more often than the left. As a result of concomitant vagotonia, however, sinus node dysfunction is more common with inferior infarction. This influence, as well as a predominantly right-sided circulation, also makes AV nodal block more frequent with such infarctions. Bradyarrhythmias due to sinus or AV nodal dysfunction often require only observation. If symptomatic, they are usually responsive to vagolytic or chronotropic drugs, but may necessitate pacemaker therapy often only on a temporary basis. The distal conduction system including the bundle branches is supplied mainly, but not exclusively, by the left anterior descending artery. Thus, acute bundle branch block is often associated with anterior MI. The indications for both temporary and permanent prophylactic pacing in this situation remain controversial. Several authors have made recommendations based on risk stratification. We would temporarily pace patients with anterior or indeterminate infarctions and new right or left bundle branch block, and probably those with bilateral bundle branch block of indeterminate age. All patients with new bilateral or alternating bundle branch block should be paced, regardless of infarct site. Permanent prophylactic pacing would appear indicated in patients exhibiting alternating bundle branch block or perhaps new right bundle branch block and left posterior hemiblock. In contrast to this group, the treatment of patients who develop sudden complete heart block, whether transient or permanent, is clear-cut. These patients require continuous (temporary followed without interruption by permanent) pacemaker therapy (Table 3).

Syncope and Bilateral Bundle Branch Block

Syncope and Bilateral Bundle Branch Block

Conduction disturbance and tachyarrhythmia in postoperative ventricular septal defect and tetralogy of Fallot.

The importance of conduction disturbances and tachyarrhythmias as the determining factors of the late results of postoperative patients with ventricular septal defect and tetralogy of Fallot was reconfirmed in this follow-up study. It was found, however, that the incidences of complete heart block, bilateral bundle-branch block, and ventricular tachyarrhythmia have decreased significantly since the establishment of cold cardioplegia. This has certainly contributed to the remarkable improvement in late follow-up results of postoperative patients with ventricular septal defect or tetralogy of Fallot.

Atrioventricular block complicating amiodarone-induced hypothyroidism in a patient with pre-excitation and rate-dependent bilateral bundle branch block

As a clinical entity atrioventricular (AV) block due to hypothyroidism is rare. Such a case induced by hypothyroidism complicating long-term therapy with amiodarone in a 45 year old woman with pre-excitation is presented. Electrophysiologic data obtained before and during thyroxine replacement therapy showed that hypothyroidism lengthens the effective refractory period of the atria, AV node, bypass tract and His-Purkinje system (that in the ventricle not being measured); this lengthening resembles the effects of long-term administration of amiodarone. These observations suggest that depressed thyroid function may be protective against arrhythmias but a patient with preexisting conduction system disease may develop AV block. The tendency to develop AV block in a patient who is euthyroid was reduced by bypass tract conduction. These findings are significant not only in monitoring amiodarone effects during chronic prophylactic drug therapy but also in providing further insight into the complex interrelation between the action of the drug and the thyroid hormones on cardiac muscle.