Narrow Complex Supraventricular Tachycardia Research Articles

AP-452681-4 UNUSUAL INITIATION OF ORTHODROMIC ATRIOVENTRICULAR REENTRANT TACHYCARDIA WITH A JUNCTIONAL BEAT

Spontaneous initiation of orthodromic atrioventricular reentrant tachycardia (AVRT) is commonly noted with premature ventricular beat (PVC). In the lab it can be initiated with programmed atrial or ventricular stimulation. We report the initiation of AVRT (with left lateral accessory pathway) with a junctional beat. Case report A 69-year-old male with history of Parkinson’s, HTN, who has had palpitations for few years. Event monitor showed narrow and wide complex tachycardia and he was scheduled for electrophysiology (EP) study and catheter ablation. He presented in sinus rhythm. EP study revealed normal AH and HV intervals with no evidence of preexcitation. Narrow complex supraventricular tachycardia (SVT) initiated spontaneously as noted in the Figure. SVT (short RP) was also initiated with ventricular and atrial extra stimuli without critical AH dependence. There was eccentric atrial activation during SVT with the earliest atrial activation on distal CS. Ventricular overdrive pacing (VOD) during SVT lead to VAV response ruling out atrial tachycardia. There was LBBB during SVT that increased the VA time from 94 ms to 170 ms. The tachycardia terminated with single fused PVC with VA block. Based on these findings a diagnosis of AVRT was made and the concealed left lateral accessory pathway was ablated at 1’o clock on mitral annulus via transseptal catheterization. This case illustrates spontaneous initiation of AVRT using a left lateral accessory pathway with a junctional beat that conducted retrogradely through the accessory pathway. This is a novel finding that has not been demonstrated prior to this. Hence a junctional beat can spontaneously initiate AVRT similar to a PVC. Similarly JPC can initiate AVNRT especially during ablation at the slow pathway region and should not be presumed to be junctional tachycardia.

Mitral Valve Disease in Thyroid Storm

Introduction: The cardiovascular effects that thyroid gland causes are widely studied. In fact, there is a known correlation between Graves’ Disease and mitral valve damage. We present the case of a patient admitted with thyroid storm and heart failure associated with severe structural damage of the mitral valve papillary muscle. Case Report: 24 year old woman with hyperthyroidism diagnosed 12 years ago, treated irregularly with thiamazole and propranolol, leaving treatment a year ago, presents dyspnea, class III functional capacity, diarrhea and logic dysphagia of a month of evolution. Heart rate over 170 bpm, respiratory rate 48 rpm and blood pressure 143/84 mmHg. Physical exam positive for exophthalmos, grade III goiter, crackles in both lung bases, pretibial myxedema and fulfilling criteria for a thyroid storm (65 points in Burch-Wartofsky Point Scale).First Lab Results: TSH<0.005µU/mL, free T4>7.7ng/dl and TRAB 37.8UI/L. Chest ray: Global cardiomegaly and pulmonary edema. EKG: Narrow complex supraventricular tachycardia. Thyroid ultrasound: Intrathoracic goiter. Transesophageal echocardiogram: Severe mitral insufficiency (Carpentier Type I and IIIB), right cavities and left ventricular enlargement, preserved right ventricular function and severe pulmonary hypertension (PSAP 71-76 mmHg).First treated with thiamazole, hydrocortisone IV, cholestyramine and sedation, falling time after into ventilatory failure and developing delirium, requiring invasive mechanical ventilation. Tested positive for COVID- 19. Starts preparation with Lugol and undergoes Total Thyroidectomy. After surgery develops severe hypocalcemia secondary to transitory hypoparathyroidism.During hospitalization presents multiple infections including pneumonia (Pseudomonas Aeruginosa), lung aspergillosis, bacteriuria (Enteroccocus Faecium) and candiduria (Candida Albicans and Glabrata), each one treated with multiple antibiotics and vasoactive drugs. Once stable, mitral valve replacement is realized, after which, the patient progresses favorably being discharged with programmed ambulatory controls. Conclusion: We report a case of a patient who was presented with positive thyroid storm criteria associated with heart failure and severe mitral valve insufficiency. The case gets complicated as multiple infections take place, including COVID-19. Fortunately, because of the early and aggressive multidisciplinary management, the patient evolved favorably, overcoming the life-threatening conditions she went through. Key Words: Thyroid storm, mitral valve insufficiency, heart failure. Bibliography: Klein I, Danzi S. Thyroid disease and the heart. Circulation. 2007 Oct 9;116(15):1725-35. doi: 10.1161/CIRCULATIONAHA.106.678326. Erratum in: Circulation. 2008 Jan 22;117(3):e18. PMID: 17923583.

The Role of Coronary Computed Tomography Angiography in Evaluation of High Troponin Patients with Narrow-Complex Supraventricular Tachycardia.

Aim:The aim of this study was to investigate the relation of high-sensitive cardiac troponin T (hs-cTnT) elevation with characteristics of supraventricular tachycardia (SVT) episode (duration and maximum heart rate) and coronary computed tomography angiography (CCTA) findings in patients with SVT who presented to the emergency room with palpitation.Methods:This retrospective, single-center, noninvasive study included all patients aged between 18 years and 65 years who presented to the emergency department due to narrow-complex SVT and underwent CCTA to rule out coronary artery disease (CAD) due to elevation of hs-cTnT and reverted back to sinus rhythm after intravenous adenosine. The first, second, and the maximum hs-cTnT levels were obtained from the database. The patients were classified into normal coronaries, nonobstructive CAD, and obstructive CAD according to findings of the CCTA. The findings of the groups were compared.Results:Eighty-five patients were enrolled in the study. Of them, 21 (26%) patients were female. Sixty-three patients (74%) had normal coronary arteries as per CCTA results, whereas 22 patients (22%) had nonobstructive CAD and two patients (2%) had obstructive CAD. The groups did not differ statistically in respect to hs-cTnT measurements, duration of the arrhythmia, and maximum heart rate at SVT episode. There was no significant statistical correlation between hs-cTnT and the study parameters except the maximum heart rate.Conclusion:Cardiac troponins may increase in patients with paroxysmal SVT irrespective of the presence of coronary lesions, and the CCTA may not be an appropriate investigation in the differential diagnosis of paroxysmal SVT with elevated hs-cTnT.

Inadvertent triggering of supraventricular tachycardia during pacemaker interrogation: Time to lose the magnet?

A 22-year-old male had a dual chamber permanent pacemaker (PPM) implanted for complete heart block following aortic valve replacement for Shone’s syndrome 3 months previously. He presented with acute shortness of breath due to severe para-valvular leak with aortic valve dehiscence following a motor vehicle accident. He was scheduled for redo sternotomy and a pre-operative PPM check was undertaken. A programmer wand (Model 2067, Medtronic Inc., Minneapolis, MN, USA) was applied to the patient's PPM site to perform interrogation. During initialization, asynchronous DOO pacing at the magnet rate of 85 bpm was initiated with evidence of both atrial and ventricular capture. Competition from intrinsic rhythm resulted in functional loss of capture. Competitive pacing initiated a narrow complex supraventricular tachycardia at 180 bpm. The tachycardia persisted to result in clinical deterioration until reversion with urgent intravenous metoprolol. Programmer wands from Medtronic (Model 2067 & Encore) and Biotronik (Renamic, Biotronik Inc., Berlin, Germany) have in-built magnets that can cause asynchronous pacing during initialization of interrogation. Removing the magnet in future iterations of PPM programmer wands will mitigate inadvertent arrhythmia induction.<Learning objective: Some pacemaker programmer wands contain in-built magnets that can initiate asynchronous pacing when placed over a cardiac implantable electronic device. This could result in asynchronous pacing and inadvertent triggering of arrhythmia. This risk can be minimized by placing the wand after the programmer is booted up to reduce the duration of asynchronous pacing. Device manufacturers should consider redesigning their products to make magnets redundant in future models of programming wands.>

Radiofrequency ablation of regular narrow complex supraventricular tachycardia in elderly and pediatric

BackgroundRadiofrequency (RF) catheter ablation is a well established approach in treating several types of cardiac arrhythmias whether supraventricular or ventricular and is in many cases the first choice therapy. Radiofrequency ablation has been shown to be effective and safe with a success rates ranging from 80% to 100%.Furthermore, few studies had investigated the efficacy and safety of catheter ablation in elderly patients and pediatrics patients. ObjectivesThis study is prospective evaluation of the safety and efficacy of radiofrequency ablation of regular narrow complex supraventricular tachycardia in both age extremes, elderly and pediatric patients. MethodsThe study included 30 patients, 19 patients >60 years [group I] and 11 pediatric patients <14 years [group II], referred to National Heart Institute and Critical Care Department at Kasre AL-Ainy Cairo University hospital from October 2008 to October 2009 who underwent electrophysiological study and radiofrequency catheter ablation to symptomatic supraventricular tachyarrhythmia, medically refractory. ResultsThirty patients had ablated presented with variable clinical characteristics in both groups. The AVRT is more frequent in higher age group however the AVNRT is almost equally distributed in both age group only two cases atrial flutter and atrial tachycardia. The success rate in group I was 90% and in group II was 100%. No complications were recorded in group I and in group II the only recorded complication was complete heart block in one patient that required permanent pacemaker insertion, also recurrence rate was zero in group two but two patients in group one show recurrence at 6 months follow up. ConclusionWe have concluded that catheter ablation of supraventricular tachycardia is a very good option for management of patients with drug resistant SVT in both young and old patients. The success rate was very high almost with no complications and very low recurrence rate in the elderly and no recurrence in the young during the 6 months follow-up.

Long-RP supraventricular tachycardia with 1:1 AV relationship: What is the mechanism?

A 24-year-old woman was seen in the clinic with a 5-year history of intermittent palpitations. Ambulatory monitoring recorded frequent episodes of regular narrow-complex supraventricular tachycardia (SVT) at a rate of 170 beats/min. After informed consent was obtained, she was taken to the electrophysiologic laboratory for diagnostic evaluation and treatment. Four catheters were placed in the standard locations: high right atrium, His bundle position, right ventricular outflow tract, and coronary sinus.

Wenckebach During Supraventricular Tachycardia

In case 1, a 71-year-old man with a history of coronary artery disease presented with recurrent paroxysmal supraventricular tachycardia (SVT) despite treatment with β-blockers. During electrophysiology study, the baseline sinus cycle length was 895 ms, atrial-His (AH) interval was 120 ms, and His-ventricular interval was 60 ms. A narrow complex SVT with tachycardia cycle length of 480 ms was initiated with atrial overdrive pacing at 400 ms, as well as with single atrial extrastimuli. The tachycardia showed a long RP interval with regular concentric atrial activation pattern and atrioventricular Wenckebach conduction (Figure 1). Ventricular overdrive pacing during tachycardia repeatedly terminated the tachycardia without activation of the atrium (Figure 2). Figure 1. Inducible SVT with Wenckebach block above the His (arrows) in patient 1 (ECG leads I, III, V1, and V6). His d indicates distal His; His p, proximal His; CS 1,2, distal coronary sinus; CS 7,8, proximal coronary sinus; and RVa, right ventricular apex. Figure 2. Ventricular overdrive pacing terminates tachycardia with ventriculoatrial block (arrow) (ECG leads I, III, V1, and V6 …

Significant arrhythmias associated with Interleukin-2 therapy

2588 Background: A side effects of Interleukin-2 (IL-2) is the vascular leak syndrome. High dose IL-2 produces a reduction of mean arterial pressure and systemic vascular resistance as well as increased heart rate and cardiac output similar to early septic shock. Cardiac arrhythmias have been reported in 14–21% of the patients undergoing IL-2 therapy. Methods: A retrospective study of 92 patients treated at OLMMC with IL-2 for renal cell carcinoma and or melanoma in 2003was done. Patients age ranged from 24 to 74 years (mean of 56 years). Eligibility criteria included normal left ventricular systolic function, normal pulmonary function tests, normal stress test (no evidence of cardiac ischemia), normal renal function, resected locally advance or metastatic renal cell carcinoma, no prior systemic therapy and excellent organ function. All patients treated with IL-2 either high dose or intermediate dose were monitored. EKGs performed before initial infusion demonstrated normal sinus rhythm. Results: Patients included 52 male (56.6%) and 40 females (43.4%). Ten male and eight female patients developed cardiac arrhythmias. Eight patients had AF (8.7%), 8 patients had narrow complex supraventricular tachycardia (8.7%), 2 patients had ventricular tachycardia (0.2%). AF was treated with iv and/or po diltiazam. SVT was treated with iv diltiazem and digoxin; VT was treated with iv procainamide, diltiazam and digoxin. All arrhythmias resolved. Among the 15 patients treated with high dose IL-2, 6 (6.5%) developed AF, 2 (0.2%) developed VT, and 7 (46.6%) developed SVT. Two patients treated with intermediate dose IL-2 developed AF, and 1 developed SVT. The most striking electrolyte imbalances were hyperkalemia and hypercalcemia, although below parameters for arrhythmias. Conclusions: 19.56% of patients treated with iv IL-2 showed significant cardiac arrhythmias that necessitated iv and po management. Several patients required po treatment at home, especially the patients with AF. The patients with AF responded to diltiazem with no need for long-term anticoagulation with warfarin. The VT resolved without sequelae. Despite careful cardiac pre-screening, IL-2 can induce Arrythmias thru physiologic pathways. Therefore, cardiac monitoring continues to be necessary. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Chiron Chiron Chiron

Part 6: Advanced Cardiovascular Life Support

Part 6: Advanced Cardiovascular Life Support

Effect of bundle branch block on local electrogram morphologic features: Implications for arrhythmia diagnosis by stored electrogram analysis

Analysis of stored local ventricular electrogram recordings is a useful diagnostic tool in the evaluation of patients with implantable cardioverter defibrillators. Visual analysis of local electrogram morphologic features has been demonstrated to be useful in distinguishing ventricular tachycardia from supraventricular rhythm. The effect of bundle branch block (BBB) aberration during supraventricular tachycardia on local electrogram morphologic features is not entirely clear. Erroneous diagnoses resulting from a change in electrogram morphologic features with BBB may occur. To determine whether the development of BBB can produce a change in local electrogram morphologic features and whether this change is dependent on the site of recording, we retrospectively reviewed local electrogram recordings from 23 patients who had intermittent BBB during electrophysiologic evaluation of documented or suspected supraventricular tachycardia. Local electrogram recordings from catheters placed in the right ventricular apex and coronary sinus during supraventricular tachycardia with BBB aberrancy were compared with recordings during narrow complex supraventricular tachycardia or normal sinus rhythm. Bipolar recordings were made with a 5 mm inter-electrode distance with filter settings at 40 to 400 Hz. Three independent blinded observers defined the paired electrograms as the same or distinctly different. During right BBB a change in electrogram morphologic features was demonstrated in 11 (85%) of 13 recordings from the right ventricular apex and in only 1 (8%) of 12 recordings from the coronary sinus. In contrast, during left BBB a change in electrogram morphologic features was seen in 6 (100%) of 6 recordings from the coronary sinus and in only 1 (8%) of 13 recordings from the right ventricular apex. These results demonstrate that when the described recording techniques are used, a change in local ventricular electrogram morphologic features during BBB is predominantly manifest in recording sites ipsilateral to the BBB, whereas recording sites contralateral to the BBB are relatively unaffected. This information may have implications regarding interpretation of stored electrograms when an attempt is made to establish a rhythm diagnosis leading to implantable cardioverter defibrillator therapy.

A Comparison of Adenosine and Verapamil for the Treatment of Supraventricular Tachycardia in the Prehospital Setting

Study objective: To compare the efficacy and base hospital physician use of adenosine with that of verapamil in the prehospital treatment of supraventricular tachycardia (SVT). Design: A 12-month prospective chart review of adenosine administration and a 12-month retrospective chart review of verapamil administration. Setting: A single-tier advanced life support emergency medical service system. Participants: Prehospital adult patients presenting with narrow-complex SVT. Interventions: Field paramedics identified SVT. They then administered verapamil or adenosine under on-line physician medical control. Paramedics administered up to two IV doses of verapamil, 2.5 mg and 5 mg, or up to two IV doses of adenosine, 6 mg and 12 mg. They recorded ECG readings; blood pressure; pulse; respirations; and symptoms before, during, and after drug administration. Results: During the verapamil period, paramedics identified 102 cases of SVT and administered verapamil to 17 patients. Review by a cardiologist revealed 6 of the 17 patients to have been in atrial fibrillation, atrial tachycardia, or sinus tachycardia. Of the remaining 11 patients, 7 (64%) converted from SVT to sinus rhythm. During the adenosine period, paramedics identified 89 cases of SVT, and they administered adenosine to 64 patients. Eight patients had no review because prehospital rhythm strips were lost. Of the remaining 56 patients, 24 were later determined to have been in atrial fibrillation, atrial tachycardia, sinus tachycardia, atrial flutter, or ventricular tachycardia. Of the remaining 32 patients who were in SVT, adenosine converted 25 (78%) to sinus rhythm. An important incidental finding was the misinterpretation of tachydysrhythmias in 30 of 73 patients by paramedics and base hospital physicians. Conclusion: Our study showed no difference in conversion rates between verapamil and adenosine. Base hospital physicians were more likely to order adenosine than verapamil. Paramedics and base hospital physicians often misinterpret tachydysrhythmias. [Madsen CD, Pointer JE, Lynch TG: Comparison of adenosine and verapamil for the treatment of supraventricular tachycardia in the prehospital setting. Ann Emerg Med May 1995;25:649-655.]

Termination of supraventricular tachycardia with intravenous adenosine in a pregnant woman with Wolff-Parkinson-White syndrome

Pregnancy is associated with an increased frequency of arrhythmias in women with Wolff-Parkinson-White syndrome. We describe the use of intravenous (IV) adenosine for the acute termination of a narrow complex tachycardia in a pregnant patient with this syndrome.A 26-year-old woman with known Wolff-Parkinson-White syndrome presented with dizziness, palpitations, and a narrow complex supraventricular tachycardia. We used IV adenosine to convert the arrhythmia to a normal sinus rhythm. During labor, the patient again developed a narrow complex supraventricular tachycardia, and fetal monitoring revealed recurrent deep variable decelerations. Intravenous adenosine resulted in conversion to sinus rhythm and restoration of the fetal heart rate to normal. Cesarean delivery produced a healthy male infant.Adenosine is effective in rapidly terminating maternal narrow complex tachyarrhythmias before and during delivery in women with Wolff-Parkinson-White syndrome. It can also treat fetal bradycardia resulting from the maternal arrhythmia.

Evaluation and Treatment of Narrow Complex Tachycardias

Narrow complex supraventricular tachycardia can occur transiently related to an acute illness or recur intermittently on a chronic basis. These disturbances are frequently treated in the emergency room or in the intensive care unit. Clinical electrophysiology testing has resulted in a better understanding of the different types of supraventricular tachycardias. The acronym PAT and junctional tachycardia were previously used to describe a narrow complex tachycardia that had an abrupt onset and abrupt termination. These arrhythmias, now termed paroxysmal supraventricular tachycardias (PSVT) are known to arise by different electrophysiologic mechanisms. Terms such as PAT and junctional tachycardia should be discarded for more precise terminology when possible. The term PSVT is used to describe a general category of supraventricular tachycardias.

Atrioventricular Nodal Supraventricular Tachycardia with 2:1 Block above the Bundle of His

A patient with narrow complex supraventricular tachycardia underwent electrophysiological study at which time a tachycardia was initiated which had 2:1 AV conduction, with block occurring above the His bundle. The modes of tachycardia initiation, as well as the responses to atrial and ventricular premature depolarizations during tachycardia, made a diagnosis of atrioventricular nodal reentry as the tachycardia mechanism. The unusual finding of 2:1 supra-His block suggests the presence of tissue situated between the tachycardia circuit and His bundle, and effectively excludes the possibility of a His-atrial bypass tract as the retrograde limb of the tachycardia circuit.

ADENOSINE IN THE DIAGNOSIS OF BROAD COMPLEX TACHYCARDIA

Adenosine, in incremental bolus doses up to 0·25 mg/kg, was given during regular broad complex tachycardia in 26 patients examined in an electrophysiological laboratory. In 8 of 9 cases of broad complex supraventricular tachycardia (SVT) the arrhythmia was terminated, converted into a narrow complex SVT, or atrioventricular block was induced. In all 9 cases of narrow complex SVT, the arrhythmia was stopped, or atrioventricular block was induced. The arrhythmia was stopped in only 1 of 17 cases of ventricular tachycardia. 6 patients with atrial fibrillation and ventricular pre-excitation were given adenosine, with no effect on mean ventricular rate (averaged over 3 s), although a significant, but short-lived, reduction in minimum RR interval was observed (from 242 ms, SD 45, to 217 ms, SD 39). The mean dose of adenosine required to stop the arrhythmia or to induce atrioventricular block in broad complex SVT (0·14 mg/kg, SD 0·04) was higher than in narrow complex SVT (0·11 mg/kg, SD 0·04). No adverse haemodynamic effects were observed in any patient, and large doses were tolerated by the patients with ventricular tachycardia. The data show that adenosine has a useful role in the diagnosis and treatment of regular broad complex tachycardia.