Predictors of Trypanosoma cruzi PCR positivity in patients with chronic Chagas disease.

BACKGROUND: A positive Trypanosoma cruzi polymerase chain reaction (PCR) is associated with a worse prognosis in patients with chronic Chagas disease (CD). OBJECTIVES: To study the association of clinical, electrocardiographic, and echocardiographic characteristics and biomarker blood levels with positive T. cruzi PCR in chronic CD. METHODS: This is a single-centre observational cross-sectional study. Positive T. cruzi PCR association with clinical, electrocardiographic, and echocardiographic characteristics, and biomarker blood levels were studied by logistic regression analysis. p values < 0.05 were considered significant. FINDINGS: Among 333 patients with chronic CD (56.4% men; 62 ± 10 years), T. cruzi PCR was positive in 41.1%. Stepwise multivariate logistic regression showed an independent association between positive T. cruzi PCR and diabetes mellitus {odds ratio (OR) 0.53 [95% confidence interval (CI) 0.30-0.93]; p = 0.03}, right bundle branch block [OR 1.78 (95% CI 1.09-2.89); p = 0.02], and history of trypanocidal treatment [OR 0.13 (95% CI 0.04-0.38); p = 0.0002]. Among patients with a history of trypanocidal treatment (n = 39), only four (10%) patients had a positive T. cruzi PCR. MAIN CONCLUSIONS: Among several studied parameters, only diabetes mellitus, right bundle branch block, and history of trypanocidal treatment showed an independent association with positive T. cruzi PCR. History of trypanocidal treatment was a strong protective factor against a positive T. cruzi PCR.

Recovery of complete left bundle branch block in a dilated cardiomyopathy patient after treatment with sacubitril/valsartan: A case report.

RATIONALE: The treatment of dilated cardiomyopathy (DCM) has recently been greatly improved, especially with the widespread use of sacubitril/valsartan (ARNI) combination therapy. We know that ARNI-like drugs can significantly improve the symptoms of heart failure with reducing ejection fraction. However, clinical studies evaluating the safety and efficacy of ARNI in DCM-associated arrhythmia are limited, and whether individuals with arrhythmia would benefit from ARNI remains controversial. In this case, we report a patient with complete left bundle branch block (CLBBB) associated with DCM whose CLBBB returned to normal after treatment with ARNI. PATIENT CONCERNS: A 38-year-old man was admitted to the hospital for 20 days for idiopathic paroxysmal dyspnea. He presented with exacerbated dyspnea symptoms at night, accompanied by cough and sputum. DIAGNOSIS: Physical examination revealed a grade 4/6 systolic murmur could be heard in the apical area of the heart and mild edema was present in both lower limbs. Laboratory examination found that the B-type natriuretic peptide was significantly increased. Echocardiography indicated left atrial internal diameter, right ventricular internal diameter, and left ventricular diastolic diameter were enlarged and ejection fraction was significantly decreased. Besides, the pulsation of the wall was diffusely attenuated. Electrocardiogram was suggestive of tachycardia and CLBBB. A diagnosis of DCM with CLBBB was considered based on a comprehensive evaluation of the physical examination, laboratory examination, echocardiography and electrocardiogram. INTERVENTIONS: The patient was treated with ARNI at a dose of 50 mg (twice a day) at first, gradually increasing to the target dose (200 mg, twice a day) in the following 9 months as shown in Table 1, along with metoprolol 25 mg (once a day [qd]), diuretics 20 mg (qd), and aldosterone 20 mg (qd). OUTCOMES: After treatment with ARNI during the 9-month follow-up, the patient's symptoms improved, and CLBBB returned to normal. LESSONS: Clinical studies evaluating the safety and efficacy of ARNI in DCM-associated arrhythmia are limited, and whether individuals with arrhythmia would benefit from ARNI remains controversial. This report will help to instruct the clinical treatment of DCM patients with CLBBB and the potential application of ARNI.

Amiodarone in patients with left bundle branch block: how to assess the QT interval?

Amiodarone is commonly used for the treatment of supraventricular and ventricular arrhythmias. As a class III antiarrhythmic drug, it prolongs phase III of the cardiac action potential leading to QT interval prolongation. Therefore, the QTc interval should be monitored during amiodarone up-titration to prevent proarrhythmia. However, QTc monitoring in bundle branch block requires some modification as outlined in this case report. The normal upper value of QT interval has been set at 450 ms for males and 460 ms for females. Patients with preexisting bundle branch block (BBB) by definition exhibit wider QRS intervals, ranging between 120 and 200 ms. This 'augmented' QT interval duration is mainly driven by the prolonged time of ventricular depolarization, rather than the time of ventricular repolarization. This inherent QT interval prolongation in BBB can be corrected with specifically designed electrocardiographic formulas. Nevertheless, accurate QT interval calculation at very low or high heart rates remains challenging.

Rare Association of Takotsubo Cardiomyopathy with Right Bundle Branch Block in the Dual Setting of Asthma Exacerbation and Psychiatric Illness.

BACKGROUND Takotsubo cardiomyopathy is characterized by a transient left ventricular dysfunction without obstructive coronary artery disease that mimics an acute myocardial infarction. The electrocardiogram findings of Takotsubo cardiomyopathy usually present with ST-segment elevation or depression, T-wave inversion, left bundle branch block or high-grade atrioventricular block. CASE REPORT This is a report of a case of a 58-year-old male diagnosed with Takotsubo cardiomyopathy that occurred in the setting of an acute asthma exacerbation and psychiatric exacerbation with novel electrocardiogram findings of right bundle branch block. Transthoracic echocardiogram showed a preserved ejection fraction with left ventricular apical ballooning and hyperkinesis of the basal segments. The nuclear stress test showed a fixed perfusion defect at the apical segment, but the patient refused further testing such as coronary angiography. The patient was managed medically, and a repeat echocardiogram done after 8 weeks from discharge showed a complete resolution of the apical ballooning. CONCLUSIONS It is important to recognize that patients with psychiatric illness and asthma exacerbation are predisposed to develop Takotsubo cardiomyopathy. It is also reasonable to suspect Takotsubo cardiomyopathy in the presence of new electrocardiogram findings aside from those typically seen in acute myocardial infarction, especially if it is associated with apical ballooning.

Arrhythmias in Severe Trazodone Overdose.

BACKGROUND Trazodone is widely used in the treatment of depression, anxiety, and insomnia. It is thought to have a safe cardiac profile due to the relative lack of anticholinergic effects. Publications about cardiac toxicities of trazodone are scant. CASE REPORT A 55-year-old woman presented with acute disorder of consciousness secondary to an intentional trazodone overdose. She was found to have seizure activity without cerebral edema. The initial electrocardiogram was unremarkable, with a normal QTc interval. She eventually developed QTc prolongation that evolved into ventricular tachycardia, and then into a transient right bundle-branch block, left anterior fascicular block, and variable degrees of atrioventricular nodal blocks at 12-24 h after ingestion. She then developed generalized tonic-clonic seizures, cardiogenic shock, and respiratory arrest. She was intubated and treated with antiepileptics, norepinephrine, and dopamine infusion. QTc interval prolongation gradually resolved and the various forms of heart block did not recur after at 24-36 h. She did not require transcutaneous pacing, and was successfully extubated with intact neurological function. CONCLUSIONS Fatal arrhythmias can occur in trazodone overdose. Close monitoring and supportive care are crucial for patient survival.

Case study of thyrotoxic cardiomyopathy.

We present the case of a 65-year-old woman who was referred urgently from primary care with worsening breathlessness for 3 weeks, associated with tachycardia and left bundle branch block (LBBB). She had a background of type 2 diabetes, asthma and hypertension. Initial ECG revealed atrial fibrillation with the fast ventricular rate on the background of LBBB. ECHO findings were consistent with systolic impairment. Initial testing including checking thyroid function test revealed hyperthyroidism. It became evident that this patient had thyrotoxic cardiomyopathy. Early advice from the endocrine team was sought and the patient was treated with a combination of carbimazole and ivabradine. After a hospital stay, she made a remarkable recovery.

Cardiac Memory: A Case Report and Review of the Literature.

BACKGROUND: A variety of clinical syndromes can cause T-wave inversion (TWI), ranging from life-threatening events to benign conditions. One benign cause of TWI is cardiac memory, which is characterized by the transient inversion of T-waves following abnormal activation of the ventricles, commonly due to intermittent left bundle branch block (LBBB), tachydysrhythmias, electrical pacing, or ventricular pre-excitation. CASE REPORT: A 72-year-old man presented to the emergency department with chest pain, nausea, vomiting, and headache. Upon arrival, his electrocardiogram (ECG) showed new-onset LBBB with appropriate secondary ST-T wave changes. A subsequent ECG showed disappearance of LBBB and newly inverted T-waves in precordial leads V1-V5, followed by a repeat ECG that again showed LBBB. Serial troponin testing was unremarkable. During hospitalization, echocardiogram and nuclear perfusion stress test were normal. The transient TWIs in this patient were believed to be due to cardiac memory. We performed a literature review and identified 39 published cases of cardiac memory. The most common etiology for cardiac memory was after cardiac pacemaker placement, followed by intermittent LBBB (as was seen in our patient), and post-tachydysrhythmia. Patient ages ranged from 21 to 88 years, with an equal number of cases reported in men and women. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Cardiac memory is a poorly understood, rarely observed phenomenon that can occur in the setting of intermittent LBBB. Testing for acute cardiac ischemia and underlying coronary artery disease is still recommended, as the diagnosis of cardiac memory can only be made after negative workup.

Heart rate reduction after ivabradine might be associated with reverse electrical remodeling in patients with cardiomyopathy and left bundle branch block.

Left bundle branch block increases the risk of death in patients with chronic heart failure. We herein report four clinical cases of patients with chronic heart failure caused by nonischemic cardiomyopathy with left bundle branch block that occurred when adding ivabradine to optimal medical therapy, resulting in reverse electrical and mechanical remodeling. This phenomenon might be explained by the effect of ivabradine on reverse remodeling of the left ventricle with improvement of intraventricular conduction.

Cocaine-induced pseudo-Wellens' syndrome: a Wellens' phenocopy.

Wellens' syndrome represents critical occlusion of the proximal left anterior descending coronary artery. Electrocardiographic changes similar to Wellens' wave are not exceptional to acute coronary occlusion and can also be seen in cardiac and non-cardiac conditions, such as left ventricular hypertrophy, persistent juvenile T wave, bundle branch blocks, cerebral haemorrhage, pulmonary oedema, pulmonary embolism, pheochromocytoma, Takotsubo syndrome, digitalis and cocaine-induced coronary vasospasm. Cocaine-induced pseudo-Wellens' syndrome should be considered as one of the differentials, since cocaine is used frequently by young adults and can cause left anterior descending coronary vasospasm mimicking Wellens' syndrome. Initiation of the beta-blocking agent in pseudo-Wellens' syndrome as a part of acute coronary syndrome management can be disastrous. We illustrated a case of cocaine-induced pseudo-Wellens' syndrome presented with typical chest pain associated with Wellenoid ECG.

Neonatal complex arrhythmias possibly related to a TTN mutation.

We describe a neonate born with complex arrhythmias that included concurrent atrial and ventricular tachycardias. Genetic testing demonstrated a mutation in the TTN gene, which codes for titin, a large protein found in striated muscle sarcomeres. The complex arrhythmias were successfully treated with amiodarone and flecainide. The patient remains asymptomatic with normal biventricular function. We speculate that the complex arrhythmias and TTN gene mutation may be related.

Ranolazine in treatment of stable angina in woman with atrial fibrillation and intermittent left bundle branch block - a case report.

Stable angina is the most frequent manifestation of ischemic heart disease (IHD) in women as compared to men (65% versus 37%). IHD in women has more favorable clinical course because myocardial infarction develops twice as rare as in men. Coronary angiography of angina patients demonstrates normal coronary arteries more frequently in women than in men. Microvascular angina (MVA) is found to be a rather common form of stable IHD as that particular diagnosis is made later in 20-30% of patients who previously underwent coronary angiography. The disease occurs three times as often in women than in men irrespective of age. Most of these patients are in their perimenopausal age - 45-60 years. The major role in MVA development is considered to be decreased coronary flow reserve resulting from evident endothelial dysfunction of minor coronary arteries. MVA is characterized by great variability of its course and low response to conventional antianginal therapy, particularly in women. In view of this the problem of antianginal drugs which can be used in addition to standard therapy remains to be solved. Ranolazine is a new original antianginal medicine which improves left ventricular diastolic filling by selective inhibition of late Na-flow leading to more effective coronary vessels filling in diastole. The article presents the results of multicenter studies of ranolazine as to its effect on diastolic and systolic functions of the left ventricle, clinical manifestations of angina and heart failure as well as the data on antiarrhythmic action of ranolazine. This article describes the case of successful use of ranolazine as an additional anti-anginal medicine in the 46- year-old female patient diagnosed with microvascular angina. Before taking ranolazine, on the background of conventional treatment of coronary heart disease, the patient developed stable angina and persistent left bundle branch block, atrial fibrillation. After receiving ranolazine, 1000 mg per day for a month, Holter ECG monitoring showed not only significantly reduced number of strokes, the left bundle branch block and atrial fibrillation dissappeared as well. The results indicate a high efficiency of ranolazine as an antianginal, anti-ischemic and anti-arrythmic medicine.

From left bundle branch block to Icelandic whales: the multiple perils of atrial fibrillation management in the elderly.

We present the case of an elderly woman which demonstrates how AF therapy in aged individuals is particularly challenging for the presence of complex conditions. The rhythm- or the rate control strategy must be carefully chosen based on individual risk profile. Oral anticoagulant therapy must be wisely managed to maximize benefits-in terms of stroke and dementia control-and to reduce complications.

Association of left bundle branch block with obstructive coronary artery disease on coronary CT angiography: a case-control study.

AIMS: Left bundle branch block (LBBB) is considered an unfavourable prognostic marker in patients with underlying heart disease. Testing for coronary artery disease (CAD) is often prompted by incidental LBBB finding, but published studies disagree about a significant association between LBBB and CAD. We therefore assessed the association of LBBB with previously unknown CAD in patients undergoing coronary computed tomography angiography (CCTA). METHODS AND RESULTS: We enrolled 818 patients (mean age 57.2 ± 11.1 years, 106 patients with presumably new LBBB and 712 controls) without known CAD who underwent 64-slice CCTA. Image quality was assessed for each coronary segment. Comparison of obstructive CAD prevalence (defined as ≥50% stenosis) was performed using triple case-matching for pre-test probability (based on age, gender, and symptom typicality) in 101 LBBB patients and 303 matched controls with diagnostic quality in all segments. We found no difference in obstructive CAD prevalence between LBBB patients and matched controls (15 vs. 16%, P = 0.88). Similarly, there were no significant differences in cardiovascular risk factors (CVRF), stenosis severity, CAD extent, non-obstructive CAD, and vessel-based analysis between patient groups. Image quality was very high in LBBB patients and comparable to controls. On multivariate analysis, age, gender, typical angina, and CVRF, but not LBBB (P = 0.94), emerged as significant and independent predictors of obstructive CAD. CONCLUSION: CAD prevalence is similar in LBBB patients at low-to-moderate pre-test probability compared with controls with similar CVRF matched for age, gender, and symptom typicality. CCTA is a useful imaging modality in LBBB patients, providing comparable image quality to non-LBBB controls.

Verapamil-sensitive idiopathic left ventricular tachycardia in a 6-month-old: unique considerations in diagnosis and management in an infant.

Idiopathic left ventricular tachycardia of the Belhassen type is rare in infants. We present a 6-month-old infant girl with a wide-complex tachycardia with right bundle branch block QRS morphology, a superior axis, and atrioventricular dissociation, consistent with a left anterior fascicular tachycardia. Initial echocardiogram revealed depressed ventricular function. The tachycardia was unresponsive to therapeutic trials of adenosine, esmolol, procainamide, and lidocaine. There was brief conversion of the tachycardia to sinus rhythm with transesophageal atrial overdrive pacing, suggesting a reentrant mechanism of the arrhythmia. Ultimately, the judicious administration of intravenous verapamil resulted in termination of the arrhythmia, which has been sustained on oral therapy.

Ventricular fibrillation induction and diffuse abnormal ST-segment response to ajmaline in a patient with apparent pre-existing dynamic right bundle branch block.

OBJECTIVE: ST-segment elevation in the right precordial electrocardiography (ECG) leads in Brugada syndrome (BS) can be unmasked by class I anti-arrhythmic drugs (sodium channel blockers) administration. It is still debated whether this ECG pattern is better explained by abnormal repolarization or ventricular conduction and depolarization. Conduction diseases can conceal type 1 BS-like ECG in standard V1-V3 leads. ECG alterations were found also in alternative leads. The role of electrophysiology study (EPS) in sudden cardiac death risk stratification remains controversial, and could depend on the phenotypic expression of the cardiac sodium channels disease. CASE REPORT: We describe unmasked diffuse J-point and ST-segment anomalies in peripheral and precordial ECG leads and ventricular fibrillation (VF) induction by EPS after ajmaline administration in a patient with pre-existing atypical right bundle branch block (RBBB) concealing subtle anomalies in standard V1-V3 leads. RBBB was influenced by the underlying BS-like ECG associating repolarization anomaly and pre-existing conduction disease. EPS induced VF when RBBB was associated with BS-like ECG, and failed to induce VF when RBBB was present alone. CONCLUSIONS: BS phenotype heterogeneity requires further studies to improve the knowledge of its pathophysiological mechanisms associated with conduction diseases in order to better identify an individual therapy and prognostic stratification.

Verapamil-sensitive fascicular ventricular tachycardia in a patient with isolated left ventricular noncompaction.

Isolated left ventricular noncompaction (IVNC) is a rare congenital form of cardiomyopathy. Verapamil-sensitive fascicular ventricular tachycardia is a rare arrhythmogenic condition characterized by a right bundle-branch block pattern and left-axis deviation with a relatively narrow QRS complex. We herein present the case of a patient with IVNC who presented with verapamil-sensitive fascicular ventricular tachycardia.