Comparison of remote magnetic versus manual catheter navigation for ablation of atrioventricular nodal reentry tachycardia

Objective The purpose of this study was to compare remote magnetic catheter navigation with manual navigation for the ablation of atrioventricular nodal reentry tachycardia （AVNRT）. Methods From November 2007 to November 2009, 30 consecutive patients with AVNRT received radiofrequency ablation in the Institute of Geriatric Cardiology. Of them, 14 were treated with remote magnetic navigation （RMN） and 16 with manual catheter navigation （MCN）. Total fluoroscopic time,procedure time, procedural success rate, and complication rate were compared between the two groups. Results Total fluoroscopy time and precise orientation time were reduced in RMN group compared to MCN group （7.5＋0.3 min vs 13.9~5.3 rain, and 1.0-x-0.3 min vs 3.2：~0.6 min, respectively, both P〈0.05）. Procedural success rates in both groups were 100% and no AVNRT recurred in all patients during 3 months＇ follow-up. The number of lesions delivered was less for RMN group （3.4~1.1 vs 6.3＋2.2, P〈0.05）. Total procedure time （25.6~7.5 rain vs 27.5a：6.2 rain,/〉〉0.05） was similar between the 2 groups. No procedural complications occurred in both groups. Conclusions RMN for mapping and ablation of AVNRT significantly reduce precise orientation time, total fluoroscopy time and number of lesions delivered compared to the conventional technique of manual steering of deflectable catheters. Remote magnetic control mapping and ablation of AVNRT is more safe and feasible （J Geriatr Cardio12010; 7：7-9）.

Plasma natriuretic peptides during supraventricular tachycardia: A study in patients with atrioventricular nodal reentry tachycardia

Aims: To characterize the plasma levels of the atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) in patients with atrioventricular nodal reentry tachycardia (AVNRT), we measured the plasma levels of these peptides before and during tachycardia. Methods: We included 10 consecutive patients scheduled for ablation of typical AVNRT without structural heart disease. Catheters were inserted in the femoral artery, femoral vein, and coronary sinus (CS) prior to the ablation procedure. Blood samples were drawn before and after 3 min of tachycardia to measure plasma levels of ANP and BNP. Right atrial pressure (RAP) was measured at baseline. Results: Of the 10 patients, in three patients it was not possible to induce tachycardia leaving a total of 7 patients available for analysis. Mean age of the seven included patients was 40 ± 12 years (mean ± SD), five were female. ANP levels increased significantly during tachycardia in the artery (p = 0.0009) and vein (p = 0.003), but only borderline in CS (p = 0.09). BNP levels did not change during tachycardia in any location. Conclusion: ANP levels measured in the peripheral circulation increased acutely during tachycardia due to AVNRT. BNP levels did not increase.

Unexplained fetal tachycardia:A case report

BACKGROUND This study aimed to explore the possible etiology and treatment of severe fetal tachycardia in the absence of organic disease and provide a reference for clinical management of severe fetal tachycardia.CASE SUMMARY A 29-year-old pregnant woman,with a gravidity 1 parity 0,presented with a fetal heart rate(FHR)of 243 beats per minute during a routine antenatal examination at 31+2 wk of gestation.Before termination of pregnancy at 38 wk of gestation,the FHR repeatedly showed serious abnormalities,lasting more than 30 min.However,the pregnant woman and the fetus had no clinical symptoms,and repeated examination revealed no organic lesions.The mother and the baby were regularly followed up.CONCLUSION This was a case of severe fetal tachycardia with no organic lesions and management based on clinical experience.

Peripartum Cardiomyopathy Complicated by Ventricular Tachycardia during Labor: A Case Report and Literature Review

Background: Peripartum cardiomyopathy (PPCM) is a rare disease that typically affects young, healthy women. Because PPCM is associated with significant mortality, timely diagnosis and management are essential. Ventricular tachycardia (VT) is a major complication and contributor to sudden death. Available data on VT in patients with PPCM are limited. Aim: This case report demonstrates the clinical presentation, antenatal care, and management of labor and delivery in a patient with PPCM complicated by VT. Case report: 36-year old patient G4P3 presents at 27 weeks gestation to the emergency department complaining of chest tightness, palpitations, and profuse sweating. Peripartum cardiomyopathy was diagnosed after her last pregnancy a few years prior. Ventricular tachycardia was diagnosed at this visit and treated successfully. The remainder of the pregnancy was uneventful until she had another episode of ventricular tachycardia during labor. Treatment using antiarrhythmics (diltiazem, amiodarone, adenosine) highlights the importance of prompt intervention and the need for a range of therapeutic options. Results: This case demonstrated successful VT management during pregnancy and labor, emphasizing multidisciplinary collaboration, influencing maternal and fetal outcomes positively, providing insights into optimal care strategies. Conclusion: Peripartum cardiomyopathy complicated by ventricular tachycardia is a life-threatening combination. This case highlights the importance of timely diagnosis and management with combined care between cardiologists, maternal fetal medicine specialists and anesthesiologists to prevent morbidities and sudden maternal death.

Massive inferior wall aneurysm presenting with ventricular tachycardia and refractory cardiomyopathy requiring multiple interventions:A case report

BACKGROUND Inferior wall left ventricular aneurysms are rare,they develop after transmural myocardial infarction(MI)and may be associated with poorer prognosis.We present a unique case of a large aneurysm of the inferior wall complicated by ventricular tachycardia(VT)and requiring surgical resection and mitral valve replacement.CASE SUMMARY A 59-year-old male was admitted for VT one month after he had a delayed presentation for an inferior ST-segment elevation MI and was discovered to have a large true inferior wall aneurysm on echocardiography and confirmed on coronary computed tomography(CT)angiography.Due to the sustained VT,concern for aneurysm expansion,and persistent heart failure symptoms,the patient was referred for surgical resection of the aneurysm with patch repair,mitral valve replacement,and automated implantable cardioverter defibrillator insertion with significant improvement in functional and clinical status.CONCLUSION Inferior wall aneurysms are rare and require close monitoring to identify electrical or contractile sequelae.Coronary CT angiography can outline anatomic details and guide surgical intervention to ameliorate life-threatening complications and improve performance status.

Wide QRS complex tachycardia in a patient with wide QRS complex sinus rhythm due to left bundle branch block pattern

A 58-year-old man with hypertension and half a year ago documented left bundle branch block(LBBB)in his past history presented with progressive dyspnea.A pre-admission echocardiography showed severely depressed systolic left ventricular function[ejection fraction(EF)=27%],diffuse hypokinesis and dilated heart chambers consistent with dilated cardiomyopathy(DCM).

Antitachycardia pacing programming in implantable cardioverter defibrillator:A systematic review

Implantable cardioverter defibrillator(ICD) programminginvolves several parameters. In recent years antitachycardia pacing(ATP) has gained an increasing importance in the treatment of ventricular arrhythmias, whether slow or fast. It reduces the number of unnecessary and inappropriate shocks and improves both patient's quality of life and device longevity. There is no clear indication regarding the type of ATP to be used, except for the treatment of fast ventricular tachycardias(188 bpm-250 bpm) where it has been shown a greater efficacy and safety of burst compared to ramp; 8 impulses in each sequence of ATP appears to be the best programming option in this setting. Beyond ATP use, excellent clinical results were obtained with programming standardization following these principles: extended detection time in ventricular fibrillation(VF) zone; supraventricular discrimination criteria up to 200 bpm; first shock in VF zone at the maximum energy in order to reduce the risk of multiple shocks. The MADIT-RIT trial and some observational registries have also recently demonstrated that programming with a widespread use of ATP, higher cut-off rates or delayed intervention reduces the number of inappropriate and unnecessary therapies and improves the survival of patients during mid-term follow-up.

Diagnosis and management of postural orthostatic tachycardia syndrome：A brief review

Postural orthostatic tachycardia syndrome （POTS） has been recognized since at least 1940.A review of the literature identifies differences in the definition for this condition and wide variations in treatment and outcomes.This syndrome appears to describe a group of conditions with differing pathophysiology,which requires treatment tailored to the true underlying disorder.Patients need to be fully evaluated to guide treatment.Further research is required to effectively classify the range of underlying pathophysioiogy that can produce this syndrome and to guide optimal management.

Repetitive narrow QRS tachycardia in a 61-year-old female patient with recent palpitations

A 61-year-old female patient suffering from recent onset palpitations and dyspnea on exertion with hypertension and mitral valve prolapse in her past history came to our outpatient department. Echocardiography revealed a mild mitral valve prolapse, slightly decreased left ventricular （LV） function （LV ejection fraction： 51%） and a mild mitral regurgitation.

Assessment of slow pathway function after successful radiofrequency modification in patients with typical AV nodal reentry tachycardia by the use of the maximal AH interval

Background Persistence of slow pathway (SP) function after SP modification is not uncommon after successful rediofrequency (RF) ablation of typical AV nodal reentry tachycardia (AVNRT). Methods and results We compared two methods (maximal AH interval during decremental atrial stimlation vs occurrence of AV nodal echos or dual AV nodal physiology (DAVNP): ≥50 msec increment in AH interval with a 10 msec decrement in A1A2) for the assessment of SP function immediately and 40 minutes after successful RF modification of SP. In 31 consecutive patients (age: 51±16 years, 18 women, 13 men) with typical AVNRT, SP modification was performed using a combined anatomic and electrogram guided approach. Immediately after successful SP modification, AV nodal function was assessed. This was repeated 40 minutes later. RF modification of SP was successful in all 31 patients. There was no recurrance during a 5±3 month follow up period. There was no significant difference between the electrophysiological parameters immediately and University of Frankfurt, Germany (Li YG, Bogun F, Grnefeld G, Hohnloser SH and Goethe JW)40 min after successful SP modification. There was evidence of SP function in 14 patients (6 with DAVNP+AV nodal echoes, 8 with either DAVNP or AV nodal echos) immehiately after SP modification. These patients could be differentiated from the patients without remaining SP function by maximal AH interval (298±102 msec vs 198±72 msec, P=0.004). 40 minutes after the suucessful SP modification, 11 patients displayed SP function (4 patients with DAVNP+AV nodal echos, 7 patients with either DAVNP or AV nodal echos). These patients could also be differentiated from the remaining patients with the use of the maximal AH interval (294±89 msec vs 189±50 msec, P<0.001).[BHDFG3,WK9ZQ,WK6,WK10*2,WK5W]Befroe SP modificationImmediately after RF40 min after RF[BHDZG1*2,WK9ZQ,WK6,WK10*2,WK5W]AVNERP (msec)258±44310±116316±114AVBCL (msec)330±55384±113376±110VABCL (msec)306±67306± 66311±54Max AH (msec)337±96247±100233±86 Conclusion SP function assessed immediately and 40 minutes after a successful SP modification remains stable. SP function can be assessed reliable by maximal AH interval during decremental atrial stimulation.

Ventricular tachycardia ablation and substrate modification in ICD patients with electrical storm

The electrical storm （ES） is defined as a state of electrical instability with three or more sustained ventricular arrhythmias （VAs） occurring within twenty-four hours, which needs intravenous antiarrhythmic medications and frequent defibrillation. Recently, radiofrequency catheter ablation evolved as a sole therapy to terminate ES in patients with ICD, and the survival has been reported to be improved with successful ablation during follow-up. In this review, we briefly summarize substrate mapping and substrate ablation strategy in patients with ES, and discuss the reason of recurrence after ablation.

Discrimination of ventricular tachycardia and localization of its exit site using surface electrocardiography

Differential diagnosis of supraventricular tachycardia (SVT) and ventricular tachycardia (VT) is of paramount importance for appropriate patient management. Several diagnostic algorithms for discrimination of VT and SVT based on surface electrocardiogram (ECG) analysis have been proposed. Following established diagnosis of VT,a specific origination tachycardia site can be supposed according to QRS complex characteristics. This review aims to cover comprehensive and comparative description of the main VT diagnostic algorithms and to present ECG characteristics which permit to suggest the most common VT origination sites.

Rare presentation of intralobar pulmonary sequestration associated with repeated episodes of ventricular tachycardia

Arterial supply of an intralobar pulmonary sequestration(IPS) from the coronary circulation is extremely rare. A significant coronary steal does not occur because of dual or triple sources of blood supply to sequestrated lung tissue. We present a 60-year-old woman who presented to us with repeated episodes of monomorphic ventricular tachycardia(VT) in last 3 mo. Radio frequency ablation was ineffective. On evaluation, she had right lower lobe IPS with dual arterial blood supply, i.e., right pulmonary artery and the systemic arterial supply from the right coronary artery(RCA). Stress myocardial perfusion scan revealed significant inducible ischemia in the RCA territory. Coronary angiogram revealed critical stenosis of proximal RCA just after the origin of the systemic artery supplying IPS. The critical stenosis in the RCA was stented. At 12 mo follow-up, she had no further episodes of VT or angina.

Low doses of intravenous epinephrine for refractory sustained monomorphic ventricular tachycardia

We report three cases of sustained monomorphic ventricular tachycardia(VT) in the setting of coronary artery disease,resistant to beta-blockers in two patients and to amiodarone in all,successfully terminated by low doses of intravenous(IV) epinephrine.VT was the first manifestation of coronary artery disease in one patient,whereas the other two patients had a previous history of myocardial infarction and were recipients of an implantable cardioverter-defibrillator(ICD).One of these two patients experienced an arrhythmic storm.All had hemodynamic instability at the time of epinephrine administration.A single slow administration of IV epinephrine(0.5 to 1 mg administered over 30 to 60 s) restored sinus rhythm after 30-90 s with only minor side effects.In the ICD patient with recurrent VT and several cardioversions due to transformation of VT to ventricular fibrillation,epinephrine injection led to the avoidance of further shocks.Although potentially harmful,low doses of IV epinephrine used alone or in combination with beta-blocker treatment and electrical cardioversion may be an alternative effective therapy for sustained monomorphic VT refractory to amiodarone.The role of epinephrine in the termination of VT should be studied further,especially in patients pre-treated with amiodarone in combination with beta-blockers.

Investigations for the assessment of adult patients presenting to the emergency department with supraventricular tachycardia

Dear editor,Patients with supraventricular tachycardia(SVT)commonly present to the emergency department(ED).Current guidelines[1,2]do not recommend routine pathology testing and a report on the topic has questioned their role.A systematic review concluded that troponin testing is commonly performed with a high proportion of positive fi ndings,but these results were not associated with major adverse cardiac events.[3]The conclusions of this review were limited by paucity of data and heterogeneity among studies.

Novel approaches for the treatment of ventricular tachycardia

Ventricular tachycardia(VT) is a crucial cause of sudden cardiac death(SCD) and a primary cause of mortality and morbidity in patients with structural cardiac disease. VT includes clinical disorders varying from benign to lifethreatening. Most life-threatening episodes are correlated with coronary artery disease, but the risk of SCD varies in certain populations, with various underlying heart conditions, specific family history, and genetic variants. The targets of VT management are symptom alleviation, improved quality of life, reduced implantable cardioverter defibrillator shocks, prevention of reduction of left ventricular function, reduced risk of SCD, and improved overall survival. Antiarrhythmic drug therapy and endocardial catheter ablation remains the cornerstone of guideline-endorsed VT treatment strategies in patients with structural cardiac abnormalities. Novel strategies such as epicardial ablation, surgical cryoablation, transcoronary alcohol ablation, pre-procedural imaging, and stereotactic ablative radiotherapy are an appealing area of res-earch. In this review, we gathered all recent advances in innovative therapies as well as experimental evidence focusing on different aspects of VT treatment that could be significant for future favorable clinical applications.

Differential diagnosis of tachycardia with a typical left bundle branch block morphology

The evaluation of wide QRS complex tachycardias (WCT)remains a common dilemma for clinicians.Numerous algorithms exist to aid in arriving at the correct diagnosis.Unfortunately,these algorithms are difficult to remember,and overreliance on them may prevent cardiologists from understanding the mechanisms underlying these arrhythmias.One distinct subcategory of WCTs are those that present with a"typical"or"classic" left bundle branch block pattern.These tachycardias may be supraventricular or ventricular in origin and arise from functional or fixed aberrancy,bystander or participating atriofascicular pre-excitation,and bundle branch reentry.This review will describe these arrhythmias,illustrate their mechanisms,and discuss their clinical features and treatment strategies.

Management of ventricular tachycardia storm in patients with structural heart disease

Electrical storm(ES) is a medical emergency characterized by repetitive episodes of sustained ventriculararrhythmias(VAs) in a limited amount of time(at least 3 within a 24-h period) leading to repeated appropriate implantable cardioverter defibrillator therapies. The occurrence of ES represents a major turning point in the natural history of patients with structural heart disease being associated with poor short-and longterm survival particularly in those with compromised left ventricular ejection fraction(LVEF) that can develop hemodynamic decompensation and multi-organ failure. Management of ES is challenging with limited available evidence coming from small retrospective series and a substantial lack of randomized-controlled trials. In general, a multidisciplinary approach including medical therapies such as anti-arrhythmic drugs, sedation, as well as interventional approaches like catheter ablation, may be required. Accurate patient risk stratification at admission for ES is pivotal and should take into account hemodynamic tolerability of VAs as well as comorbidities like low LVEF, advanced NYHA class and chronic pulmonary disease. In high risk patients, prophylactic mechanical circulatory support with left ventricular assistance devices or extracorporeal membrane oxygenation should be considered as bridge to ablation and recovery. In the present manuscript we review the available strategies for management of ES and the evidence supporting them.

Trigger elimination of polymorphic ventricular tachycardia and ventricular fibrillation by catheter ablation:trigger and substrate modification

Ventricular fibrillation （VF） is a malignant arrhythmia, usually initiated by a ventricular premature contraction （VPC） during the vulnerable period of cardiac repolarization. Ablation therapy for VF has been described and increasingly reported. Targets for VF triggers are VPCs preceded by Purkinje potentials or from the right ventricular outflow tract （RVOT） in structurally normal hearts, and VPC triggers preceded by Purkinje potentials in ischemic cardiomyopathy. During the session, mapping should be focused on the earliest activation and determining the earliest potential is the key to a successful ablation. However, suppression of VF can be achieved by not only the elimination of triggering VPCs, but also by substrate modification of possible reentry circuits in the Purkinje network, or between the PA and RVOT. The most important issue before the ablation session is the recording of the 12-lead ECG of the triggering event, which can prove invaluable in regionalizing the origin of the triggering VPC for more detailed mapping. In cases where the VPC is not spontaneous or inducible, ablation may be performed by pace mapping. Further studies are needed to evaluate the precise mechanisms of this arrhythmia.

Efficacy and economic benefits of a modified Valsalva maneuver in patients with paroxysmal supraventricular tachycardia

BACKGROUND A modified Valsalva maneuver(VM)has been suggested to be superior to the standard VM for conversion of paroxysmal supraventricular tachycardia(PSVT).AIM To evaluate the efficacy and economic benefits of a modified VM in Chinese patients.METHODS Patients with PSVT admitted to our center between October 2017 and September 2019 were randomly assigned to the modified and standard VM groups.Conversion via VM was performed up to three times.The primary outcome of the study was the success rate of PSVT conversion to sinus rhythm.The secondary outcomes included the incidence of adverse events,economic cost during the visit,and the degree of patient acceptance of the treatment.RESULTS Overall,361 patients were enrolled,with 180 allocated to the modified VM group and 181 to the standard VM group.Baseline characteristics were well matched in the groups.Overall,the modified VM group had higher success rates of PSVT conversion after single(47.78%vs 15.38%,P<0.001)and multiple(62.22%vs 19.78%,P<0.001)VM sessions.No significant differences in the incidences of adverse events and rates of patient acceptance were detected between the two groups(both P>0.05).Moreover,the economic cost of the clinic visit was significantly lower for the modified VM group than for the standard VM group(P<0.05).CONCLUSION The modified VM may confer both therapeutic and economic benefits as compared with the standard VM for conversion of PSVT.