Polymorphic Ventricular Tachycardia Due to Acute Coronary Ischemia: A Case Report

Acute myocardial ischemia can cause ventricular tachycardia (VT) in patients with structurally normal heart. Contrary to the fact that in patients with chronic myocardial scarring the ventricular tachycardia is monomorphic, in patients with acute ischemia the ventricular tachycardia is polymorphic and is reversible with coronary revascularization.We are reporting a 40 year old male who presented with recurrent syncope due to polymorphic ventricular tachycardia in the context of normal QT interval in baseline ECG and normal left ventricular function without any evidence of myocardial injury. Due to recurrent fatal ventricular arrhythmia despite medical management, urgent coronary angiography was done which showed critical obstruction of right coronary artery (RCA). Considering the critical obstruction of RCA responsible for polymorphic VT, emergency PCI of RCA was done. After successful PTCA and stenting to RCA, he had another episode of polymorphic VT which was terminated with intravenous phenytoin. Seven days after the PCI, 24 hours Holter monitoring was done which showed normal sinus rhythm with infrequent ventricular premature complexes and no evidence of VT. He was asymptomatic at six months follow-up.     

Focal Monomorphic Ventricular Tachycardia As The First Manifestation Of Amyloid Cardiomyopathy

52-year-old patient presented with palpitation and well tolerated monomorphic ventricular tachycardia. He had normal echocardiogram and coronary angiogram 3 months prior to presentation. Surface EKG revealed regular wide-complex tachycardia with right bundle branch block morphology and right inferior axis. In conjunction with recent negative cardiac evaluation, this suggested idiopathic focal ventricular tachycardia from anterolateral basal left ventricle. CARTO based activation mapping confirmed the presence of VT focus in that area. Radiofrequency ablation at the site of perfect pacemap resulted in a partial suppression of the focus. Echocardiogram was subsequently performed because of progressive dyspnea. It revealed asymmetrical thickening of posterolateral left ventricle, with delayed enhancement on contrast magnetic resonance imaging. Fine needle aspiration of abdominal fat stained with Congo red confirmed the diagnosis of systemic AL amyloidosis due to IgG λ-light chain deposition. Consequently, the patient underwent placement of implantable defibrillator and hematopoetic stem cell transplantation. He remains in excellent functional status 18 months after presentation.     

Wolff-Parkinson-White syndrome with an unroofed coronary sinus without persistent left superior vena cava treated with catheter cryoablation

Coronary sinus anomalies are rare congenital defects which are usually coexistent with a persistent left superior vena cava and may be associated with cardiac arrhythmias. We report an unroofed coronary sinus without persistent left superior vena cava diagnosed during a catheter ablation procedure for Wolff-Parkinson-White syndrome. Diagnostic and therapeutic options and outcomes are discussed. This condition is of relevance to electrophysiologists performing catheter-based procedures, as well as cardiologists implanting coronary sinus pacing leads, who may encounter this anomaly in their practice.     

Peripartum Cardiomyopathy Presenting With Ventricular Tachycardia: A Rare Presentation

A 25-year-old previously asymptomatic pregnant woman at 36 weeks'' gestation was noticed to have repetitive monomorphic ventricular tachycardia. A dilated left ventricle with moderately reduced systolic function was found on echocardiographic examination. This is a very rare presentation of peripartum cardiomyopathy (PPCMP) presenting with repetitive monomorphic ventricular tachycardia.     

An Alternative Way to Reach the Epicardial Focus of the Left Ventricular Tachycardia in a Patient with Non-ischemic Cardiomyopathy

We report a case of a 69-year-old male with non-ischemic cardiomyopathy, having drug- and antitachycardia pacing-refractory ventricular tachycardia resulted in multiple ICD shocks. The sustained and intractable ventricular arrhythmia was mapped and ablated with the aid of the three-dimensional electroanatomic mapping system, initially performed but unsuccessful from the endocardial site then performed successfully from the epicardial site via the coronary sinus.     

A case of successful radiofrequency catheter ablation for atrial tachycardia originating from the inferior vena cava using high-resolution mapping

A 60-year-old man presented with sustained supraventricular tachycardia. Atrial tachycardia (AT), with the earliest atrial activation (EAA) occurring at the ostium of the coronary sinus, was reproducibly induced.Three-dimensional electroanatomical mapping (3DEAM) using a 3.5-mm distal electrode tip linear catheter (Thermocool) and radiofrequency energy (RF) was performed at the fractionated atrial electrogram site. It preceded at 30 ms to the EAA but did not terminate AT. Further 3DEAM using a multielectrode mapping catheter (Pentaray) demonstrated a centrifugal propagation pattern at the boundary zone between the right atrium and inferior vena cava. RF application here terminated AT, which then became non-inducible.     

Ablation of Post Transplant Atrial Flutter and Pseudo-fibrillation Using Magnetic Navigation via a Superior Approach

Ablation of cavotricuspid isthmus flutter and atrial tachycardia in a complex substrate has never been reported using remote navigation via superior approach. Venous access was obtained via right internal jugular for ablation and left subclavian for duodecapolar catheter placement into the coronary sinus. In a posttransplant patient presenting with both regular and irregular tachycardia, both cavotricuspid isthmus flutter in the donor and atrial tachycardia in the recipient was mapped using a two catheter approach. Successful ablation of typical atrial flutter and anastomotic block was achieved. This is the first report of successful ablation of cavotricuspid isthmus flutter and posttransplant atrial tachycardia using magnetic navigation via superior approach. Using only two catheters, this approach is logical and feasible in complex substrates with interrupted inferior venous access.     

Unroofed coronary sinus newly diagnosed in adult patients after corrected congenital heart disease

Patients with congenital heart disease corrected in early childhood may later in life present with cardiac symptoms caused by other associated congenital anomalies that were initially not diagnosed. Nowadays, several noninvasive imaging modalities are available for the visualisation of cardiac anatomy in great detail. We describe two patients with an unroofed coronary sinus, a rare congenital anomaly which could be diagnosed using a combination of modalities including echocardiography, cardiac CT and cardiac MRI.     

Reappraisal of resetting response to locate the antegrade pathway in slow-fast atrio-ventricular nodal re-entrant tachycardia

Typical atrio-ventricular nodal re-entrant tachycardia (AVNRT) can occasionally remain easily inducible after slow pathway (SP) modification in lower Triangle of Koch (TOK). Analysis of resetting response by delivering atrial premature depolarizations (APD) from various sites (TOK, right atrium, coronary sinus and left atrium) can pin-point the culprit SP serving as the antegrade limb of the tachycardia circuit. However, the maneuver is under-utilized by most centers. We describe a case where anatomical SP modification in TOK failed to cure the arrhythmia. The resetting maneuver performed subsequently, helped us to rule out leftward inferior extension of SP and suggested right inferior SP as essential part of AVNRT circuit. Further ablation was performed at M1-M2 region (on the right side) to achieve success.     

心血管危重症继发交感风暴37例临床分析

目的:探讨心血管危重症继发交感风暴的病因分布特点和治疗方法。方法:回顾性分析我院2001年-2011年37例心血管危重症继发交感风暴临床资料。结果:37例心血管危重症继发交感风暴患者,其中男性22例,女性15例,年龄55-82岁,平均68.25岁。病因分布为:心肌梗死29例,心衰3例,扩张性心肌病2例,电解质紊乱2例,Brugada综合征1例。治疗方法包括β受体阻滞剂、胺碘酮、利多卡因、电除颤等。其中,17例因反复发作室颤,经抗心律失常药物和电除颤治疗无效死亡,余20例病情得到控制。结论:心血管危重症继发交感风暴临床病因多样,病情凶险,应用β受体阻滞剂及抗心律失常药物,同时积极针对病因及诱因治疗,可以改善临床症状和预后。     

Ventricular tachycardia due to cardiac ischaemia: assessment by exercise electrocardiography

Although ventricular tachycardia is a well-known complication of myocardial ischaemia and may be provoked by exercise, many patients may appreciate only the angina and be unaware of the unduly rapid heart rate that precipitates it. Exercise testing is needed to show this arrhythmia and to enable treatment to be started.Twenty-three patients were found to have chronic ischaemic heart disease complicated by ventricular tachycardia. Six patients with old myocardial infarction had ventricular tachycardia at rest which required conversion to sinus rhythm; 17 patients developed ventricular tachycardia only when they exercised. In 12 of these 17 patients coronary angiography showed disease of the anterior descending branch of the left coronary artery; other vessels were usually also affected. Although beta-adrenergic blocking drugs increased exercise tolerance, ventricular tachycardia still occurred when the heart rate on exercise reached a level similar to that before treatment. In five patients coronary artery bypass surgery was performed because of angina and exercise-induced ventricular tachycardia. Exercise tolerance was increased in all three patients who underwent exercise tests after operation, and in two of these patients, both of whom were known to have patent grafts, ventricular tachycardia was abolished.If part of the beneficial effect of coronary bypass surgery is preventing life-threatening ventricular arrhythmias it is essential to detect these, and ambulatory monitoring and stress testing have a complementary role.     

Right ventricular lead implantation facilitated by a guiding sheath in a patient with severe chamber dilatation with tricuspid regurgitation

Implantation of pacemakers can be challenging in the context of dilated cardiac chambers and valvular regurgitation. We report a difficult case of single chamber pacemaker implantation in a patient with restrictrive cardiomyopathy resulting in grossly enlarged atria and severe tricuspid regurgitation. In this situation, use of a slittable guiding sheath, more typically used for coronary sinus lead implantation, greatly facilitated rapid and stable deployment of the right ventricular lead.     

Mechanically induced electrical storm as a complication of cardiac resynchronization therapy: A case report

BackgroundCardiac resynchronization therapy (CRT) has been shown to improve both the functional status and mortality of heart failure patients with left bundle branch block. Multiple recent studies suggest several mechanisms for proarrhythmia associated with CRT device.Case summaryA 51-year-old male with symptomatic non-ischemic cardiomyopathy and no previous history of ventricular arrhythmias underwent placement of a biventricular cardioverter-defibrillator. The patient developed sustained monomorphic ventricular tachycardia (VT) soon after implantation. The VT recurred despite reprogramming to right ventricular only pacing. The electrical storm resolved only after a subsequent discharge from the defibrillator caused inadvertent dislodgement of the coronary sinus lead. No recurrent VT occurred throughout 10-years follow up after urgent coronary sinus lead revision.DiscussionWe describe the first reported case of mechanically induced electrical storm due to the physical presence of the CS lead in a patient with a new CRT-D device. It is important to recognize mechanical proarrhythmia as a potential mechanism of electrical storm, as it may be intractable to device reprogramming. Urgent coronary sinus lead revision should be considered. Further studies on this mechanism of proarrhythmia are needed.     

小儿阵发性室上性心动过速37 例临床分析

目的:对比研究和评价不同方法治疗小儿阵发性室上性心动过速(PSVT)的的疗效,提高转复率。方法:回顾性分析2002.04-2011.05我院住院治疗的37例PSVT患儿的临床资料,并分析比较心律平与胺碘酮的药物转复率,构成比采用x2检验,α=0.05。结果:37例患儿中,13例治疗原发病后自动转率,24例患儿给予心律平治疗,其中1例放弃治疗,5例未见效,心律平转复率为69.77%,5例未见效患儿改用胺碘酮治疗,1例死于原发病,1例控制症状后行射频消融术治愈,胺碘酮转复率为75%,二者之间无显著差异性。结论:心律平与胺碘酮均能较好的治疗小儿PSVT,对于反复发作,药物治疗无效的小儿PSVT,射频消融术已成为最佳选择。     

Idiopathic Ventricular Tachycardia Arising From the Right Ventricular Apex

We present a rare case of idiopathic ventricular tachycardia arising from the right ventricular apex. The electrocardiographic and electrophysiological characteristics of this tachycardia are discussed.     

Successful ablation of biatrial tachycardia with preserved electrical activation of left atrial appendage by unidirectional connection via Bachmann’s bundle: A case report

A 57-year-old man underwent his seventh ablation session for atrial tachycardia (AT). His previous ablations involved several regions of the right atrium (RA) and left atrium (LA). The AT was characterized as biatrial tachycardia with a circuit involving the mitral annulus and septal RA. The AT was terminated by ablation through the insertion site of Bachmann’s bundle (BB) in both atria. After 3 months, the patient underwent his eighth ablation session because of AT recurrence. Activation maps showed that the connection from the RA to LA and vice versa was maintained via BB and the coronary sinus, respectively. The ablation target to interrupt the AT circuit was the mitral isthmus (MI), not BB, because BB supplied the electrical activation of the left atrial appendage (LAA) via a unidirectional electrical connection from the RA to LA. Ablation attempts from within the coronary sinus were performed to target the epicardial connection in the MI and led to complete blockage of the connection from the LA to RA. Otherwise, the connection from the RA to LA was preserved via BB. The patient was free of symptoms and anti-arrhythmic drugs at the 4-month follow-up. However, he had a high risk of electrical isolation of the LAA because extensive ablations had been performed; the strategy of targeting the MI contributed to the balance between preserving the electrical activation of the LAA and treating the biatrial tachycardia. Verification of the connective pathway between the two atria might be helpful to determine the optimal target.     

Change In Cycle Length During Narrow Complex Tachycardia: What Is The Mechanism?

Major spontaneous variation in cycle length during supraventricular tachycardia is quite an uncommon phenomenon, which sometimes can mislead a correct diagnosis. We describe a patient who developed spontaneous variation in cycle length during electrophysiologic study in whom the coronary sinus cannulation was extremely difficult. In this situation, careful inspection of the mechanisms associated with this variation and classic pacing maneuvers are important to make a correct diagnosis of the supraventricular tachycardia.     

Coronary artery embryogenesis in cardiac defects induced by retinoic acid in mice

BACKGROUND: Although normal coronary artery embryogenesis is well described in the literature, little is known about the development of coronary vessels in abnormal hearts. METHODS: We used an animal model of retinoic acid (RA)-evoked outflow tract malformations (e.g., double outlet right ventricle [DORV], transposition of the great arteries [TGA], and common truncus arteriosus [CTA]) to study the embryogenesis of coronary arteries using endothelial cell markers (anti-PECAM-1 antibodies and Griffonia simplicifolia I (GSI) lectin). These markers were applied to serial sections of staged mouse hearts to demonstrate the location of coronary artery primordia. RESULTS: In malformations with a dextropositioned aorta, the shape of the peritruncal plexus, from which the coronary arteries develop, differed from that of control hearts. This difference in the shape of the early capillary plexus in the control and RA-treated hearts depends on the position of the aorta relative to the pulmonary trunk. In both normal and RA-treated hearts, there are several capillary penetrations to each aortic sinus facing the pulmonary trunk, but eventually only 1 coronary artery establishes patency with 1 aortic sinus. CONCLUSIONS: The abnormal location of the vessel primordia induces defective courses of coronary arteries; creates fistulas, a single coronary artery, and dilated vessel lumens; and leaves certain areas of the heart devoid of coronary artery branches. RA-evoked heart malformations may be a useful model for elucidating abnormal patterns of coronary artery development and may shed some light on the angiogenesis of coronary artery formation.     

Prostaglandins and cardiac anaphylaxis.

Manifestations of cardiac anaphylaxis include sinus tachycardia and arrhythmias, both of which result from histamine release. The marked decrease in coronary flow, which also occurs during cardiac anaphylaxis, cannot be attributed solely to histamine release.To indirectly assess the possible role of prostaglandins in cardiac anaphylaxis, hearts from sensitized guinea pigs were challenged $\text{in}$$\text{vitro}$ in the presence of indomethacin. This resulted in a marked increase in histamine release, which caused a greater tachycardia and an increase in the incidence of arrhythmias. Moreover, for the same degree of histamine release sinus rate increments were larger in the presence of indomethacin. However, despite the enhanced cardiac dysfunction, coronary flow rate did not decrease.The results suggest that, during cardiac anaphylaxis, prostaglandins modulate histamine release and the effects of released histamine. Furthermore, since we have found that PGF_2α is released from the anaphylactic heart, we tentatively ascribe the anaphylactic reduction in coronary flow to the elaboration of PGF_2α.     

Tachycardia releases atrial natriuretic peptide in the anesthetized rabbit

In anesthetized, vagotomized rabbits the plasma concentration of immunoreactive atrial natriuretic peptide (IR-ANP) was found to be 58.5 +/- 3.4 pg/mL (n = 18) when measured using a radio-immunoassay. Tachycardia, induced by electrical pacing of the right atrium, resulted in increased plasma levels of IR-ANP. The size of the increase in IR-ANP appeared to be related to the degree of tachycardia induced. The release of IR-ANP with tachycardia was unaffected by beta-adrenergic blockade with atenolol (2 mg/kg), muscarinic blockade with atropine (2 mg/kg) or ganglionic blockade with hexamethonium (10 mg/kg). The results show that IR-ANP is released in response to tachycardia and that this does not involve a neuronal reflex.