Wide QRS tachycardia in a patient with atrial fibrillation: a case report and approach to diagnosis.

Background: Wide QRS complex (QRS) tachycardia in patients with atrial fibrillation (AF) or atrial flutter treated with antiarrhythmic drugs can occur for a variety of reasons and needs careful evaluation for appropriate management of the patient. Case summary: We report a case of wide QRS complex tachycardia in a patient with AF treated with Flecainide who received multiple external cardioversion attempts for a presumed diagnosis of ventricular tachycardia. Intravenous Diltiazem and an oral beta-blocker led to the resolution of wide QRS complex tachycardia. Discussion: Wide QRS tachycardia due to pro-arrhythmic effect or rate-dependency phenomenon of antiarrhythmic agents should be included in the differentials. In this brief report, we discuss the differential diagnosis and outline a practical approach for acute and long-term management of these patients.

Aberrancy masquerading as ventricular tachycardia: Importance of invasive electrophysiology study for diagnosis of wide complex tachycardias.

BACKGROUND: Differentiation between ventricular tachycardia (VT) and supraventricular tachycardia (SVT) with aberrancy based on the 12­lead ECG alone can be imprecise. Implantable cardiac defibrillators (ICD) may be inserted for presumed VT, particularly in patients with syncopal presentation or atypical aberrancy patterns. Accurate diagnosis of these patients facilitated by an electrophysiology study (EPS) may alter diagnosis and management. METHODS: We present a prospective collection of cases across 3 cardiac centers of consecutive patients with WCT presumed to be VT who were referred for consideration of an ICD, and in whom further evaluation including an EPS ultimately demonstrated SVT with aberrancy as the culprit arrhythmia. RESULTS: 22 patients were identified (17 male, mean age 50±13 years. Available rhythm data at the time of referral was presumptively diagnosed as monomorphic VT in 16 patients and polymorphic VT in 6 patients. Underlying structural heart disease was present in 20 (91%). EPS resulted in a diagnosis of SVT with aberrancy in all cases: comprising AV nodal re-entry tachycardia (n=10), orthodromic reciprocating tachycardia (n=3), focal atrial tachycardia (n=3), AF/AFL (n=3) and 'double fire' tachycardia (n=2). 21 (95%) patients underwent successful ablation. All patients remained free of arrhythmia recurrence at a median of 3.4 years of follow-up. ICD insertion was obviated in 18 (82%) patients, with 1 patient proceeding to ICD extraction. CONCLUSION: SVT with atypical aberrancy may mimic monomorphic or polymorphic VT. Careful examination of all available rhythm data and consideration of an EPS can confirm SVT and obviate the need for ICD therapy.

Nodal Low-Grade B-Cell Lymphoma Co-Expressing CD5 and CD10 but Not CD23, IRTA1, or Cyclin D1: The Diagnostic Challenge of a Splenic Marginal Zone Lymphoma.

The diagnosis of lymphoma is based on histopathological and immunophenotypical features. CD5 and CD10 are traditionally considered a T-cell antigen and a germinal center B-cell antigen, respectively. It is very unusual for a low-grade B-cell lymphoma (BCL) to co-express CD5 and CD10. Although the biologic basis or clinical significance of such co-expression is unclear, this rare event may pose a significant diagnostic challenge. Here, we report a case of a 63-year-old male presenting with bilateral cervical lymphadenopathy and lymphocytosis. Histologically, the nodal tumor was largely diffuse with neoplastic small atypical lymphocytes co-expressing CD5, CD10, and CD20, but not CD23 or cyclin D1. The leukemic cells in the peripheral blood exhibited hairy projections. Taking together the marked splenomegaly, involvement of lymph nodes, bone marrow, and peripheral blood, a final diagnosis of splenic marginal zone lymphoma (SMZL) was reached. The patient was alive with partial response for 10 months after immunochemotherapy. The dual expression of CD5 and CD10 is extremely unusual for low-grade BCL and may lead to an erroneous diagnosis. Integrating the findings into peripheral blood smear tests, flow cytometry, histopathology, imaging, and clinical features is mandatory to exclude other lymphoma types and to reach a correct diagnosis, particularly for a case with nodal presentation.

Orthodromic Reciprocating Tachycardia Relying on Aberrant Conduction: The Need for a Larger Circuit.

Aberrant conduction during orthodromic reciprocating tachycardia (ORT) prolongs the ventriculoatrial conduction time, which can be essential for the maintenance of tachycardia in specific cases. We searched for ORT relying on aberrancy among 220 cases in our center. Three patients showed the phenomenon of aberrancy-dependent ORT. All accessory pathways were located at the lateral regions of the atrioventricular annulus. None of them had a baseline bundle branch block (BBB). Creating a functional BBB was necessary to induce the tachycardias. In two cases, termination of tachycardias was directly associated with resolution of the aberration. In the other case, re-entry required both BBB and slow pathway conduction. We conclude that extra transseptal time caused by aberrancy can be an integral part of the ORT circuit, which explains the infrequent and unsustainable episodes of ORT in certain patients and is useful in understanding the circuit and localizing the pathway.

New-Onset Intermittent Deceleration-Dependent Left Bundle Branch Block Following Induction of General Anesthesia in a Healthy Patient: A Case Report.

This case report aims to highlight an atypical presentation of deceleration-dependent aberrancy (DDA) following the induction of general anesthesia in a patient with no known cardiac history. It emphasizes the critical role of intraoperative monitoring and the potential effects of anesthetic agents on the cardiac conduction system. A 46-year-old Hispanic male with no significant past medical or surgical history presented for surgical repair of a comminuted radial fracture. Following anesthesia induction with propofol, midazolam, and fentanyl, he developed a transient left bundle branch block (LBBB) exhibiting deceleration-dependent characteristics. Despite stable hemodynamics, the LBBB pattern appeared at heart rates below 60 beats per minute and resolved with heart rates above 90 beats per minute. This was managed intraoperatively with glycopyrrolate. Postoperative evaluations, including a 12-lead ECG, echocardiogram, and nuclear stress test, indicated normal biventricular function with a small to moderate reversible perfusion defect. The patient did not report cardiac symptoms postoperatively and did not prefer to undergo a coronary angiogram. This report underscores the importance of recognizing rate-dependent LBBB as a potential intraoperative complication, even in patients without pre-existing cardiac conditions. The transient nature of DDA, influenced by anesthetic agents and managed through careful monitoring and pharmacological intervention, highlights the necessity for vigilance in perioperative settings. This case contributes to a growing body of evidence suggesting that anesthetic management may require tailored approaches for patients experiencing or at risk for conduction abnormalities. This case illustrates the complexities of cardiac conduction disturbances such as DDA in the context of general anesthesia, serving as a reminder of the importance of thorough monitoring and the judicious use of rate-modifying drugs. It fosters a deeper understanding of the interaction between anesthesia and cardiac electrophysiology. Further research is needed to explore the mechanisms and management strategies for anesthetic-related cardiac conduction abnormalities.

Diagnostic Value of the Brugada Algorithm in Differential Diagnosis of Wide QRS Tachycardia by Electrocardiogram

PURPOSE: In dealing with wide-complex tachycardia (WCT), it is important to distinguish between ventricular tachycardia (VT), supraventricular tachycardia with aberrancy (SVTAC), and preexcited tachycardia by using an accessory pathway. The aim of this study was to investigate and compare the Brugada and the Bayesian algorithms and to analyze the parameters. METHODS: Between January 1999 and December 2003, the Brugada and the Bayesian approaches were retrospectively analyzed in 103 WCTs confirmed by electrophysiologic studies. RESULTS: Seven-eight (75) VTs and 25 SVTs were found. The sensitivity and the specificity for VT achieved by using the Brugada approach were 91.0 and 68.0%, respectively, whereas those achieved by using the Bayesian approach were 84.6 and 60.0%. In the Brugada approach, the most important step was the fourth step (odds ratio: 4.33; 95% CI: 1.75-12.14). In the Bayesian approach, triphasic rsR' or rR' morphology (odds ratio: 3.93; 95% CI: 1.46-10.56), r > or = 0.04 s or notched S downstroke or delayed S nadir > 0.06 s in the V1 or the V2 lead (odds ratio: 5.75; 95% CI: 1.26?26.28), and intrinsicoid deflection > or = 0.08 s in the V6 lead (odds ratio: 6.88; 95% CI: 1.33-27.79) were more important parameters. Seven (7) VTs of 103 tachycardias were mis-classified when the Brugada approach was used. Applying additional criteria (QRS width > 0.16 s and intrinsicoid deflection > or = 0.08 s in V6 lead), three of those VTs were diagnosed correctly. CONCLUSIONS: The Brugada algorithm achieved a lower sensitivity and specificity than those reported by Brugada et al. If both the V1 and the V6 leads do not fulfill the criteria for VT, additional parameters should be evaluated.