Loss of consciousness and convulsion induced by a ventricular tachycardia mimicking epilepsy in a patient with noncompaction cardiomyopathy: a case report

Convulsions and loss of consciousness can be caused by, among other things, arrhythmias, conduction disorders or epilepsy. In clinical practice it can be difficult to distinguish between these causes of syncope, even for well-trained specialists. Patients with cardiac syncope have a substantial risk of subsequent sudden death. We present a patient with previously unknown noncompaction cardiomyopathy in whom syncope induced by ventricular tachycardia was misinterpreted as epilepsy. We present this case report in order to underline the necessity for cardiological assessment in patients with assumed mild epilepsy or syncope of unknown origin.     

Acute and long-term outcomes of VT radiofrequency catheter ablation in patients with versus without an intramural septal substrate

IntroductionAim of this study was to evaluate efficacy and safety of ventricular tachycardia (VT) catheter ablation in patients with structural heart disease (SHD) in relation to the presence of an intramural septal substrate.MethodsConsecutive patients undergoing VT ablation between January 2019 and October 2020 were included. All patients were stratified based on the presence of relevant septal substrate and freedom from VT recurrences were analyzed.ResultsIn total, 199 consecutive patients (64.2 ± 13.0 years; 89% male; 55% ischemic cardiomyopathy (ICM)) undergoing VT ablation were included. 129/199 patients (65%) showed significant septal substrate (55/90 patients (61%) with non-ischemic cardiomyopathy (NICM) compared to 74/109 patients (68%) with ICM; p = 0.37). Acute procedural success with elimination of all inducible VTs was achieved in 66/70 patients (94%) without and in 103/129 patients (80%) with a septal substrate (p = 0.007). In the cohort including patients with a clinical FU, 15/60 patients (25%) without a septal substrate and 48/123 patients (39%) with a septal substrate experienced VT recurrence during a FU of 8.1 ± 5.9 months (p = 0.069).ConclusionPresence of septal VT substrate in patients with a structural heart disease or coronary artery disease is common. Acute success of VT catheter ablation was significantly higher and mid-term success tended to be higher in patients without a septal substrate.     

Normal Heart Ventricular Tachycardia Associated with Pregnancy: Successful Treatment with Catheter Ablation

Background

Normal heart ventricular arrhythmia occurring during pregnancy has been previously described. Whilst there are established reports of catheter ablation to treat supraventricular arrhythmia during pregnancy, there are no reports of ablation to treat ventricular tachycardia.

Case

We present the case of a 36 year old women, 31 weeks into an otherwise uncomplicated pregnancy, experiencing significant, troublesome and drug refractory tachycardia emanating from the right ventricular outflow tract.

Conclusion

We describe a successful radio frequency ablation in the third trimester of pregnancy.     

Successful Ablation of an Epicardial Accessory Pathway via the Subxiphoid Approach in a Child

Data is scarce regarding epicardial ablation in children. I herewith present a case of successful epicardial ablation in a child with previous unsuccessful attempts at endocardial ablation. This report could be used to guide further such attempts.     

Ventricular tachycardia based on cardiac sarcoidosis with a narrow QRS complex,ablated on the left ventricle free-wall

A septuagenarian female with cardiac sarcoidosis suffered from drug refractory ventricular tachycardia (VT) requiring multiple implantable cardioverter-defibrillator shocks. The QRS complex during the VT was very similar to that during sinus rhythm although the QRS width during the VT (142 ms) was relatively wider than that during sinus rhythm (107 ms). The VT exit was located on the ventricular septum close to the His-bundle recording region. However, the critical pathway of this VT was detected on the anterior free wall of the left ventricle (LV), and a radiofrequency application at that site could terminate the VT. No Purkinje potentials were recorded there during the VT or sinus rhythm. According to the electrophysiological study, 3-D mapping, and the response to the ablation, the critical circuit of the VT was surrounded by a protected area of scar associated with cardiac sarcoidosis. As a result, the VT circuit was connected to the basal septal area close to the His-Purkinje system as an outer loop of the VT circuit. This unique trajectory of the VT might have caused a similar QRS morphology to that of sinus rhythm, and the relatively narrow QRS complex despite the critical isthmus was located on the anterior free wall of the LV.     

The first human experience of a contact force sensing catheter for epicardial ablation of ventricular tachycardia

Contact force (CF) is one of the major determinants for sufficient lesion formation. CF-guided procedures are associated with enhanced lesion formation and procedural success. We report our initial experience in epicardial ventricular tachycardia (VT) ablation with a force-sensing catheter using a new approach with an angioplasty balloon. Two patients with arrhythmogenic right ventricular cardiomyopathy who underwent prior unsuccessful endocardial ablation were treated with epicardial VT ablation. CF data were used to titrate force, power and ablation time.     

Management of paroxysmal ectopic atrial tachycardia with long sinus pauses in a teenager

Sinus pauses in the setting of supraventricular tachycardia is rare in children. We describe an asymptomatic teen with irregular heart rate detected during an incidental exam who was found to have short runs of a slow ectopic atrial tachycardia on electrocardiogram and prolonged sinus pauses on routine ambulatory ECG. Successful catheter ablation of the ectopic atrial tachycardia led to resolution of the sinus pauses.     

Utility of cardiac imaging in patients with ventricular tachycardia

Ventricular tachycardia (VT) is a life-threatening arrhythmia that may be idiopathic or result from structural heart disease. Cardiac imaging is critical in the diagnostic workup and risk stratification of patients with VT. Data gained from cardiac imaging provides information on likely mechanisms and sites of origin, as well as risk of intervention. Pre-procedural imaging can be used to plan access route(s) and identify patients where post-procedural intensive care may be required. Integration of cardiac imaging into electroanatomical mapping systems during catheter ablation procedures can facilitate the optimal approach, reduce radiation dose, and may improve clinical outcomes. Intraprocedural imaging helps guide catheter position, target substrate, and identify complications early. This review summarises the contemporary imaging modalities used in patients with VT, and their uses both pre-procedurally and intra-procedurally.     

Defining the substrate for ventricular tachycardia ablation: The impact of rhythm at the time of mapping

BackgroundVoltage mapping is critical to define substrate during ablation. In ventricular tachycardia, abnormal potentials may be targets. However, wavefront of activation could impact local signal characteristics. This may be particularly true when comparing sinus rhythm versus paced rhythms. We sought to determine how activation wavefront impacts electrogram characteristics.MethodsPatients with ischemic cardiomyopathy, ventricular tachycardia, and without fascicular or bundle branch block were included. Point by point mapping was done and at each point, one was obtained during an atrial paced rhythm and one during a right ventricular paced rhythm. Signals were adjudicated after ablation to define late potentials, fractionated potentials, and quantify local voltage. Areas of abnormal voltage (defined as <1.5 mV) were also determined.Results9 patients were included (age 61.3 ± 9.2 years, 56% male, mean LVEF 34.9 ± 8.6%). LV endocardium was mapped with an average 375 ± 53 points/rhythm. Late potentials were more frequent during right ventricular pacing (51 ± 21 versus 32 ± 15, p < 0.01) while overall scar area was higher during atrial pacing (22 ± 11% vs 13 ± 7%, p < 0.05). In 1/9 patients, abnormal potentials were seen during a right ventricular paced rhythm that were not apparent in an atrial paced rhythm, ablation of which resulted in non-inducibility.ConclusionRhythm in which mapping is performed has an impact on electrogram characteristics. Whether one rhythm is preferable to map in remains to be determined. However, it is possible defining local signals during normal conduction as well as variable paced rhythms may impart a greater likelihood of elucidating arrhythmogenic substrate.     

Suppression of frequent ventricular ectopy in a patient with hypertrophic heart disease with ranolazine: a case report

Background

Pro-arrhythmic concerns with most anti-arrhythmic agents in patients with significant left ventricular hypertrophy (LVH) limits options when anti-arrhythmic therapy is indicated. Ranolazine, an anti-anginal agent which inhibits late Na+ currents, indirectly causes a decrease in diastolic cardiomyocyte Ca++ levels producing an energy sparing effect. Ranolazine also inhibits triggered activity in animal studies and has anti-arrhythmic properties in patients with ischemic heart disease. Here we report the dramatic anti-arrhythmic effects of ranolazine in a patient with frequent ventricular and supraventricular ectopy in the setting of hypertrophic heart disease without significant coronary artery disease.

Methods

A 72 year old hypertensive patient with palpitations and significant exercise intolerance due to dyspnea was evaluated with echocardiography, thallium stress testing and cardiac catheterization. Holter monitor data prior to, and after institution of ranolazine 1000 mg twice daily was compared. Patient tolerance and sense of well being after ranolazine was assessed.

Results

Significant LVH was noted and obstructive coronary artery disease was ruled out by cardiac catheterization. Within two hours of the initial dose of ranolazine a marked decrease in ventricular ectopy was observed. Ventricular ectopy on Holter monitor decreased approximately 12 fold (23.8% of beats to1.9%) while supraventricular ectopy decreased approximately 7 fold (5.3% of beats to 0.8%). The decrease in ectopy was associated with an improved sense of well being.

Conclusion

Ranolazine had rapid onset, potent anti-arrhythmic properties in the absence of obstructive coronary artery disease in a patient with LVH and may be an ideal agent in patients where few anti-arrhythmic options exist.     

Genetic variants in post myocardial infarction patients presenting with electrical storm of unstable ventricular tachycardia

Electrical storm (ES) is a life threatening clinical situation. Though a few clinical pointers exist, the occurrence of ES in a patient with remote myocardial infarction (MI) is generally unpredictable. Genetic markers for this entity have not been studied. In the present study, we carried out genetic screening in patients with remote myocardial infarction presenting with ES by next generation sequencing and identified 25 rare variants in 19 genes predominantly in RYR2, SCN5A, KCNJ11, KCNE1 and KCNH2, CACNA1B, CACNA1C, CACNA1D and desmosomal genes - DSP and DSG2 that could potentially be implicated in electrical storm. These genes have been previously reported to be associated with inherited syndromes of Sudden Cardiac Death. The present study suggests that the genetic architecture in patients with remote MI and ES of unstable ventricular tachycardia may be similar to that of Ion channelopathies. Identification of these variants may identify post MI patients who are predisposed to develop electrical storm and help in risk stratification.     

Cardiomyopathy induced by incessant ventricular tachycardia originating in the vicinity of the His bundle

A 04-year-old boy was referred to our institution with severe, progressive heart failure of 4-months duration associated with a persistent wide QRS tachycardia with left bundle branch block and severe left ventricular dysfunction. Because of incessant wide QRS tachycardia refractory to antiarrhythmic drugs, he was referred for electrophysiological study. The ECG was suggestive of VT arising from the right ventricle near the His area. Electrophysiological study revealed that origin of tachycardia was septum of the right ventricle, near His bundle, however the procedure was not successful and an inadvertent complete atrioventricular conduction block occurred. The same ventricular tachycardia recurred. A second procedure was performed with a retrograd aortic approach to map the left side of the interventricular septum. The earliest endocardial site for ablation was localized in the anterobasal region of left ventricle near His bundle. In this location, one radiofrequency pulse interrupted VT and rendered it not inducible. The echocardiographic evaluation showed partial reversal of left ventricular function in the first 3 months. The diagnosis was idiopathic parahisian left ventricular tachycardia leading to a tachycardia mediated cardiomyopathy, an extremely rare clinical picture in children.     

Successful Right Ventricular Tachycardia Ablation in a Patient with Left Ventricular Non-compaction Cardiomyopathy

We report a case of a 67-year old male with a recent diagnosis of left ventricular noncompaction (LVNC), initially presenting with symptomatic ventricular ectopy and runs of non-sustained ventricular tachycardia (VT). This ventricular arrhythmia originated in a structurally normal right ventricle (RV) and was successfully localized and ablated with the aid of the three-dimensional mapping and remote magnetic navigation.     

Unipolar and bipolar electrogram characteristics of recurrent cases of idiopathic ventricular arrhythmias undergoing repeat catheter ablation

IntroductionActivation mapping guided catheter ablation (CA) of ventricular arrhythmias (VAs) is limited in some cases when it is only relied on bipolar electrogram (EGM). We hypothesized that activation mapping with use of combined bipolar and unipolar EGM facilitates to identify the focal origin of VAs and results in reduction of recurrence rate of CA of VAs.MethodsWe analyzed the data of patients undergoing repeat ablations for idiopathic out-flow tract VAs. The EGM of the 1 st and 2 nd ablations were compared for earliest local activation time (LAT), presence of discrete potentials, and polarity reversal, unipolar potential morphology (QS or non-QS), potential amplitude and activation slope.ResultsThirty-seven patients were included. The Local activation time was significantly earlier in the 2nd ablation as compared to the 1st procedure (36.90 msec vs 31.85 msec, P < 0.01). The incidence of discrete potentials and polarity reversal were similar in both procedures (51% vs 57%, P = 0.8 and 62% in both the occasions, respectively). The unipolar voltage was similar in both occasions (6.94 mV vs 7.22 mV in repeat ablations, P = 0.7). The recurrence rate (5.7%) was significantly lower with routine use of combined unipolar and bipolar EGMs, as compared to the use of bipolar EGM alone (16.7%)ConclusionsUse of both bipolar and unipolar electrograms helps in better delineation of the sites of earliest activation for effective ablation of VAs. Use of unipolar electrograms in addition to bipolar electrograms is associated with lower long term recurrence rate.     

Acute left ventricular failure in a patient with hydroxychloroquine-induced cardiomyopathy

We present the case of a 75-year-old woman with a medical history of rheumatoid arthritis treated with hydroxychloroquine, who was admitted with acute left-sided heart failure due to a hydroxychloroquine-induced cardiomyopathy as supported by endomyocardial biopsy.     

Successful termination of ventricular tachycardia with intrinsic anti-tachycardia pacing

Intrinsic anti-tachycardia pacing (iATP) is a novel automated ATP algorithm that employs post-pacing interval (PPI) to design the next ATP sequence based on an analysis of the prior failed ATP sequence. A patient with hypertrophic cardiomyopathy received an implantable cardioverter-defibrillator (ICD) (Cobalt™ XT DR, Medtronic, Minneapolis, MN, USA) following an episode of syncope due to macro-reentrant ventricular tachycardia (VT) (right bundle branch block configuration, cycle length [CL] 280 ms). The VF zone was set to VTCL <300 ms and iATP therapy was prescribed before and during capacitor charging. The iATP was initiated when VT recurred 3 months later. The first attempt with an assumption of 150 ms propagation time from the pacing site to the VT circuit (9 pulses) could not reset the VT, leaving a PPI of 650 ms. A subsequent attempt involving 20 pulses with an assumption of 250 ms propagation time terminated the VT. Failure to reach the circuit is a major cause of unsuccessful ATP. In this regard, iATP is expected to have theoretical advantages over empirical and traditional ATP therapies. To the best of our knowledge, this is the first intracardiac electrogram illustrating how automated precision ATP terminates VT in a clinical setting.