Episodes Of Nonsustained Ventricular Tachycardia Research Articles

Triggering of Nocturnal Arrhythmias by Sleep-Disordered Breathing Events

This study sought to evaluate respiratory disturbances as potential triggers for arrhythmia in patients with sleep-disordered breathing (SDB). SDB is associated with an increased risk of atrial fibrillation and nonsustained ventricular tachycardia (NSVT) as well as a predilection for sudden cardiac death during nocturnal sleeping hours. However, prior research has not established whether respiratory disturbances operate as triggers for nocturnal arrhythmias. Overnight polysomnograms from the Sleep Heart Health Study (n = 2,816) were screened for paroxysmal atrial fibrillation and NSVT. We used the case-crossover design to determine whether apneas and/or hypopneas are temporally associated with episodes of paroxysmal atrial fibrillation or NSVT. For each arrhythmia, 3 periods of sinus rhythm were identified as control intervals. Polysomnograms were examined for the presence of respiratory disturbances, oxygen desaturations, and cortical arousals within a 90-s hazard period preceding each arrhythmia or control period. Fifty-seven participants with a wide range of SDB contributed 62 arrhythmias (76% NSVT). The odds of an arrhythmia after a respiratory disturbance were nearly 18 times (odds ratio: 17.5; 95% confidence interval: 5.3 to 58.4) the odds of an arrhythmia occurring after normal breathing. The absolute rate of arrhythmia associated with respiratory disturbances was low (1 excess arrhythmia per 40,000 respiratory disturbances). Neither hypoxia nor electroencephalogram-defined arousals alone increased arrhythmia risk. Although the absolute arrhythmia rate is low, the relative risk of paroxysmal atrial fibrillation and NSVT during sleep is markedly increased shortly after a respiratory disturbance. These results support a direct temporal link between SDB events and the development of these arrhythmias.

Characteristics and Clinical Significance of Late Gadolinium Enhancement by Contrast-Enhanced Magnetic Resonance Imaging in Patients With Hypertrophic Cardiomyopathy

Myocardial late gadolinium enhancement (LGE) on contrast-enhanced magnetic resonance imaging (CE-MRI) of patients with hypertrophic cardiomyopathy (HCM) has been suggested to represent intramyocardial fibrosis and, as such, an adverse prognostic risk factor. We evaluated the characteristics of LGE on CE-MRI and explored whether LGE among patients with HCM was associated with genetic testing, severe symptoms, ventricular arrhythmias, or sudden cardiac death (SCD). Four hundred twenty-four patients with HCM (age=55+/-16 years [range 2 to 90], 41% females), without a history of septal ablation/myectomy, underwent CE-MRI (GE 1.5 Tesla). We evaluated the relation between LGE and HCM genes status, severity of symptoms, and the degree of ventricular ectopy on Holter ECG. Subsequent SCD and appropriate implanted cardioverter defibrillator (ICD) therapies were recorded during a mean follow-up of 43+/-14 months (range 16 to 94). Two hundred thirty-nine patients (56%) had LGE on CE-MRI, ranging from 0.4% to 65% of the left ventricle. Gene-positive patients were more likely to have LGE (P<0.001). The frequencies of New York Heart Association class >or=3 dyspnea and angina class >or=3 were similar in patients with and without LGE (125 of 239 [52%] versus 94 of 185 [51%] and 24 of 239 [10%] versus 18 of 185 [10%], respectively, P=NS). LGE-positive patients were more likely to have episodes of nonsustained ventricular tachycardia (34 of 126 [27%] versus 8 of 94 [8.5%], P<0.001), had more episodes of nonsustained ventricular tachycardia per patient (4.5+/-12 versus 1.1+/-0.3, P=0.04), and had higher frequency of ventricular extrasystoles/24 hours (700+/-2080 versus 103+/-460, P=0.003). During follow-up, SCD occurred in 4 patients, and additional 4 patients received appropriate ICD discharges. All 8 patients were LGE positive (event rate of 0.94%/y, P=0.01 versus LGE negative). Two additional heart failure-related deaths were recorded among LGE-positive patients. Univariate associates of SCD or appropriate ICD discharge were positive LGE (P=0.002) and presence of nonsustained ventricular tachycardia (P=0.04). The association of LGE with events remained significant after controlling for other risk factors. In patients with HCM, presence of LGE on CE-MRI was common and more prevalent among gene-positive patients. LGE was not associated with severe symptoms. However, LGE was strongly associated with surrogates of arrhythmia and remained a significant associate of subsequent SCD and/or ICD discharge after controlling for other variables. If replicated, LGE may be considered an important risk factor for sudden death in patients with HCM.

Different Substrates of Non-Sustained Ventricular Tachycardia in Post-infarction Patients With and Without Left Ventricular Dilatation

Background We investigated the relationship between nonsustained ventricular tachycardia (NSVT) and left ventricular (LV) dilatation, function, remodeling, and scar tissue extent in patients with previous myocardial infarction (MI). Methods and Results Eighty-two patients (ages 64 ± 10 years) with first previous MI were referred for 24-hour electrocardiogram recording and cine and delayed enhancement (DE) cardiac magnetic resonance (CMR). LV volumes, ejection fraction, systolic wall thickening, sphericity index, and core and peri-infarctual areas of scar tissue by CMR were evaluated. LV dilatation was observed in 39 patients. Episodes of NSVT were recorded in 32 patients: 23 with LV dilatation and 9 without. In the entire population, NSVT was related to ejection fraction, LV volumes, LV mass, and sphericity index; end-systolic volume ( P = .001) resulted in the only independent predictor at multivariate analysis. In patients without LV dilatation, the occurrence of NSVT was only positively related with percentage of contracting segments with DE ( P = .008). Conversely, in patients with LV dilatation, increase in LV mass ( P = .020) and end-systolic volume ( P = .038) were independent predictors of NSVT. Conclusions Necrotic and viable myocardium coexistence within the same wall segments predicted occurrence of NSVT in patients without LV dilatation, whereas LV mass and end-systolic volume were predictors of NSVT in those with LV dilatation.

Identification of high risk patients with hypertrophic cardiomyopathy in a northern Greek population

BackgroundThe percentage of hypertrophic cardiomyopathy (HCM) patients who are in high risk for Sudden Death (SD) constitutes only a minority of all HCM population but the incidence of SD in this subset is high (at least 5% annually). The identification of this small but important proportion of high risk HCM patients has been the clue in the clinical evaluation of these patients.MethodsOur study cohort consisted from 123 patients with HCM who are currently followed up in our Institution. Five clinical risk factors were assessed: a family history of premature SD, unexplained syncope, Non Sustained Ventricular Tachycardia (NSVT) on 24-h ECG monitoring, Abnormal Blood Pressure Response (ABPR) during upright exercise testing and Maximum left ventricular Wall Thickness (MWT) ≥30 mm. The purpose of our study was the identification of high risk HCM patients coming from Northern Greece.ResultsFifteen patients (12.2%) of the whole cohort had MWT ≥ 30 mm, 30 patients (24.4%) had an ABPR to exercise, 17 patients (13.8%) had episodes of NSVT in 24-h Holter monitoring, 17 patients (13.8%) suffered from syncope, and 8 patients (6.5%) had a positive family history of premature SD. Data analysis revealed that 74 patients (60.1%) had none risk factor. Twenty four patients (19.5%) had 1 risk factor, 17 patients (13.8%) had 2 risk factors, 4 patients (3.25%) had 3 risk factors, and 4 patients (3.25%) had 4 risk factors, while none patient had 5 risk factors. Twenty five patients (20.3%) had 2 or more risk factors.ConclusionThis study for the first time confirms that, although a 60% of patients with HCM coming from a regional Greek population are in low risk for SD, a substantial proportion (almost 20%) carries a high risk for SD justifying prophylactic therapy with amiodaron or ICD implantation.

Ventricular fibrillation induced by a radiofrequency energy delivery for idiopathic premature ventricular contractions arising from the left ventricular anterior papillary muscle

A 73-year-old man with idiopathic premature ventricular contractions (PVCs) underwent electrophysiological testing. Left ventricular activation mapping revealed a focal mechanism of the PVCs with the earliest activation on the anterior papillary muscle (APM). Irrigated radiofrequency (RF) current delivered at that site induced a cluster of non-sustained ventricular tachycardia episodes with the same QRS morphology as the PVCs, followed by ventricular fibrillation (VF). The APM might have served as an abnormal automatic trigger and driver for the VF occurrence. Ventricular fibrillation may occur as a complication during RF catheter ablation of papillary muscle ventricular arrhythmias even if the clinical arrhythmia is limited to PVCs.

Malignant Ventricular Arrhythmia in a Case of Adult Onset of Spinal Muscular Atrophy (Kugelberg–Welander Disease)

We present a case of a 43-year-old male patient with adult onset of spinal muscular atrophy (SMA). The patient first came to our attention with atrioventricular (AV) block. A dual-chamber pacemaker (DDD-PM) was implanted. Four years later, the PM data log showed occurrence of frequent episodes of nonsustained ventricular tachycardia (NSVT). The episodes progressed in duration and frequency. An electrophysiological study revealed prolonged His-ventricular (HV) interval duration and induction of sustained ventricular tachycardia. The patient was successfully upgraded to a prophylactic dual-chamber cardioverter defibrillator. Our case is the first description of a patient with adult-onset SMA (Kugelberg-Welander disease [KWD]) and malignant ventricular arrhythmias.

Potential Application of Late Sodium Current Blockade in the Treatment of Heart Failure and Atrial Fibrillation

The cardiac action potential consists of the sequential activation of various ion channels in a precisely orchestrated manner. Pathologic alterations of ion channel currents disrupt this coordinated behavior and have been linked to arrhythmias, such as atrial fibrillation, as well as to heart failure. The late sodium current is increased in the ventricular myocytes in patients with heart failure and can result in contractile dysfunction. The most likely mechanism whereby elevated intracellular Na+ levels may lead to heart failure is through calcium overload. Sodium channel blockade is a proven strategy in the treatment of atrial fibrillation. Although all class I antiarrhythmic drugs inhibit the sodium current, ranolazine has been shown to be a more specific and potent blocker of the late sodium current. In clinical trials, ranolazine has significantly decreased episodes of nonsustained ventricular tachycardia and supraventricular tachycardia as compared with placebo.

Efeito favorável da terapia farmacológica otimizada da insuficiência cardíaca sobre as arritmias ventriculares

Ventricular arrhythmic events have a strong impact on the mortality of patients with heart failure. The benefits of the optimized drug treatment of heart failure in reducing ventricular arrhythmia have not been well documented yet. To analyze the effects of the optimized drug treatment of heart failure on ventricular arrhythmia. This is a clinical study with a non-randomized design of 85 consecutive (open cohort) non-selected patients, with a mean age of 63.8+/-12.2 years; 42 were males and 43 were females. All patients had a diagnosis of heart failure (HF), NYHA Functional Class II to IV, EF <or=0.40 and, after treatment optimization, they were followed from January 2002 to May 2004, regarding the ventricular arrhythmia behavior, at admission and at the end of the study. At the start of the study, 60% of patients presented more than 1,000 ventricular extrasystoles in 24 hours, 100% pairs and 100% nonsustained ventricular tachycardia (NSVT). During a follow-up period of 8 to 27 months (20.0 + 4.8 months) a significant decrease in the total number of ventricular extrasystoles/24 hrs, number of pairs and number of NSVT episodes was observed (p<0.05). The improvement in functional class and performance at the six-minute walk test was also observed. A decrease in hospital admissions was also observed in relation to the period prior to the study inclusion (4.8 hospital admissions/patient/year and at the end of the study, 2.7 hospital admissions/patient/year) (p<0.005). The optimized treatment of HF decreased the incidence of ventricular arrhythmias. The improvement in the functional class, physical performance and the decreased number of hospitalizations can be attributed to the optimized treatment of HF.

Usefulness of telemetry monitoring in patients with cardiac amyloidosis undergoing stem cell transplant

19543 Background: Stem cell transplant (SCT) for systemic amyloidosis with cardiac involvement includes high-dose melphalan and stem cell infusions, with resulting fluid overload, electrolyte disturbances, and infections which likely contribute to atrial (AA) and ventricular (VA) arrhythmias that are seen during SCT. However, the incidence of significant arrhythmias during SCT or the utility of telemetry monitoring (TM) has never been defined. Methods: Records from 17 consecutive patients with systemic AL amyloidosis with cardiac involvement who underwent SCT and TM were retrospectively reviewed. There were 12 men (71%) and five women, median age 53 years. The median number of AA and VA events per patient was calculated. The arrhythmia events are graded according to the Common Terminology Criteria for Adverse Events (CTCAE v3.0 8/9/06). Results: Mean length of hospital stay was 24.4 days with no in-hospital mortality. There were 121 AA events and 201 VA events (median number of AA and VA events per patient = 4 and 10, respectively. The most common arrhythmia was non-sustained ventricular tachycardia (NSVT): 159 total events, median number of patient NSVT events = 7. All 17 patients had at least one episode of NSVT (Table). Thirteen patients (76.5%) had VA of Grade 2 (CTCAE) or higher and needed medical therapy that included initiation or increase in the dose of beta-blocker or amiodarone. One patient developed sustained ventricular tachycardia and required defibrillator placement. Another patient became hemodynamically unstable during an episode of rapid atrial fibrillation and required urgent cardioversion. Conclusions: Patients with cardiac amyloidosis undergoing SCT have a high incidence of AA and VA requiring treatment. In two of 17 patients, life-threatening arrhythmias were detected and treated. Therefore, concurrent TM is warranted and contributes to patient safety during SCT. Patient grading: Maximal severity of arrhythmia events during SCT. Arrhythmia Grading (CTCAE v 3.0) AA N=patients VA N=patients VA or AA N=patients Grade 1. Asymptomatic, intervention not indicated 11 4 12 Grade 2. Non-urgent medical intervention indicated 5 12 14 Grade 3. Symptomatic, incompletely controlled medically, or controlled with device 0 0 0 Grade 4. Life-threatening 1 1 2 No significant financial relationships to disclose.

Ventricular tachyarrhythmia as a primary presentation of sarcoidosis

Sarcoidosis is a multisystem, granulomatous disease with occasional cardiac manifestations. The clinical course of patients with ventricular tachyarrhythmias as a primary presentation of sarcoidosis is mostly unknown. We describe nine patients (four males and five females) in whom sarcoidosis manifested as ventricular tachycardia (VT). The age of the patients was 53 +/- 10 years (range 33-68). The disease was diagnosed by endomyocardial biopsy in eight patients and by lymph node biopsy in one patient. The presenting arrhythmia varied from non-sustained VT to incessant VT and ventricular fibrillation. All patients received implantable cardioverter defibrillator (ICD) and anti-arrhythmic medication. High-dose steroid treatment was used in eight cases. During the follow-up (50 +/- 34 months), five patients underwent appropriate ICD therapies and non-sustained VT episodes were detected in four patients. Two patients developed incessant VT, which was treated by catheter ablation. One patient was referred for heart transplantation. Our data indicate that sarcoidosis can manifest as VT without any detectable systemic findings. This makes sarcoidosis an important diagnostic consideration in patients with VT of unknown origin. Arrhythmia control in cardiac sarcoidosis is difficult, and all modern treatments including high-dose steroids, anti-arrhythmic drugs, ICD, and catheter ablation are needed to suppress the arrhythmias.

Differences between diabetic and non-diabetic hypertensive patients with first acute non-ST elevation myocardial infarction and predictors of in-hospital complications

This investigation was undertaken to compare diabetic and non-diabetic hypertensive patients with a first acute non-ST segment elevation myocardial infarction (NSTEMI) and to assess the impact of clinical and laboratory parameters on the occurrence of in-hospital complications. The study population comprised 112 consecutive male hypertensive patients with their first NSTEMI, who were divided into two groups according to the presence of type 2 diabetes mellitus. All patients underwent echocardiography and 24-h electrocardiographic (ECG) and blood pressure monitoring within 48 h from admission. Diabetic hypertensive patients had significantly higher mean daytime, night-time, 24-h systolic blood pressure and heart rate and hypertensive peaks (P < 0.01), more episodes of asymptomatic ST segment depression (P < 0.05), which were also more severe and prolonged (P < 0.01), and more episodes of non-sustained ventricular tachycardia (P = 0.01). Diabetic patients showed a greater left ventricular mass index (LVMI) and a lower left ventricular ejection fraction (LVEF) (P < 0.01). In-hospital adverse clinical events were more frequent in diabetic hypertensives compared to non-diabetics (40.3% versus 18.1%, P = 0.01). In particular, heart failure occurred during hospitalization in 33.3% versus 14.5% (P = 0.02). The difference in transient cerebral ischaemic attacks did not reach statistical significance (7.0% versus 1.8%, P = 0.18). Multivariate Cox proportional hazards analysis showed that the only independent predictors for the occurrence of in-hospital adverse clinical events in diabetic patients were: 24-h systolic blood pressure variability [relative risk (RR) = 1.013, 95% confidence interval (CI) = 1.001-1.025, P = 0.03]; mean 24-h heart rate (RR = 7.05, 95% CI = 1.35-35.9, P = 0.02) and the LVMI (RR = 1.9, 95% CI = 1.121-3.785, P = 0.02). This study indicates that in-hospital complications, including heart failure and transient cerebral ischaemia, occur frequently during the acute phase of a first NSTEMI in patients with both diabetes and hypertension. The coexistence of diabetes and hypertension doubles the risk of complications with respect to hypertension alone. In addition, adverse events may appear despite an initial uncomplicated clinical presentation, which can be predicted by the early assessment of heart rate and blood pressure behaviour and by the echocardiographic assessment of left ventricular mass.

Diagnostic value of stored electrograms in pacemaker patients

Objective — Stored electrograms (EGMs) are diagnostic tools in modern pacemakers, providing data concerning arrhythmia occurrence and device function.We sought to validate the impact of stored EGMs on diagnosis and verification of arrhythmias presented after pacemaker implantation.Methods and results — We enrolled 71 consecutive patients (mean age 64 ± 8 years, 51 men) with a standard indication for pacemaker implantation. The following pacemaker devices were implanted:DDDR = 57, VDDR = 5, VVIR = 9. EGM triggers were atrial tachycardia (AT), non-sustained ventricular tachycardia (NSVT) and ventricular tachycardia (VT).We retrieved and analysed 362 EGMs at 3 and 6 months after implantation. The EGMs were triggered by AT in 260 EGMs (72%), by NSVT in 80 (22%) and by VT in 22 (6%). In total, 243 episodes (67%) confirmed the arrhythmic events, while 119 episodes (33%) were classified as false-positive.They were divided into false-positive AT in 85 EGMs (33%), false-positive NSVT in 28 (35%) and false-positive VT in 6 EGMs (27%). The false-positive AT cases were caused by ventricular far-field sensing from the atrial channel in 34 EGMs (40%) and noise or myopotentials in 51 EGMs (60%). Most of the false-positive VT and NSVT episodes were due to atrial fibrillation or atrial tachycardias in 21 EGMs (62%), while the rest were caused by noise in 11 EGMs (32%) or ventricular T wave oversensing in 2 EGMs (6%).Conclusions — Stored EGMs in pacemaker patients were diagnostic in two thirds of arrhythmic episodes. They are useful tools to diagnose arrhythmias and identify sensing problems, and they contribute to optimal device programming and patient management.

Tubercular myocarditis presenting with ventricular tachycardia

A previously fit and healthy 30-year-old man reported experiencing palpitations accompanied by nausea, sweating and presyncope. These symptoms were found to be associated with episodes of nonsustained ventricular tachycardia. He was a nonsmoker, did not drink excessively, denied illicit drug use and had no family history of structural cardiac disease or sudden death. Electrocardiography, laboratory tests, electrophysiological studies, echocardiography, coronary angiography, chest radiography, cardiac MRI (with late gadolinium enhancement), chest CT, lymph-node biopsy, Ziehl Nielsen staining, blood and sputum cultures and heaf testing. Tubercular myocarditis. Antituberculous chemotherapy supported by antiarrhythmic and steroid pharmacotherapy and cardioverter-defibrillator implantation. Repeated imaging was performed to monitor disease progression.

Atrial Fibrillation due to Late Amiodarone-Induced Thyrotoxicosis

A 60-year-old male patient complaining of palpitations, fatigue, weakness and weight loss of 1 month's duration was hospitalized in our cardiology department for atrial fibrillation. Thyroid function test results were compatible with thyrotoxicosis. The patient had been taking amiodarone for 2.5 years for hypertrophic obstructive cardiomyopathy and non-sustained ventricular tachycardia episodes. However, amiodarone had been discontinued after follow-up examinations revealed that the patient's ventricular arrhythmias were no longer present, and he had been taking metoprolol only for the preceding 6 months. In this patient, amiodarone-induced thyroiditis had developed 6 months after cessation of treatment, demonstrating that adverse effects may occur after discontinuation of amiodarone. Detection of the condition requires assessment of thyroid function before treatment initiation, during treatment and at regular intervals after treatment cessation. The type of hyperthyroidism induced by amiodarone cannot be determined in most cases. Patients with this condition should be referred to an experienced endocrinologist. Our case of delayed amiodarone-induced thryoiditis occcurred approximately 6 months after termination of amiodarone treatment.

Hypertrophic cardiomyopathy involving the right ventricular apex

A 19-year-old woman with hypertrophic cardiomyopathy (HCM) was referred for clinical assessment. She had no dyspnea, chest pain, syncope or family history of sudden death. The patient’s blood pressure was 100/60 mmHg, and a grade 3/6 to 4/6 systolic ejection murmur was present at the apex. Her 59-year-old mother also had HCM. An electrocardiogram showed diffuse T wave inversion. Maximum left ventricular (LV) wall thickness, as assessed by echocardiography, was 35 mm, and the Doppler-estimated LV outflow gradient at rest was 32 mmHg. The patient had a marked reduction in systolic blood pressure during upright exercise, while no episodes of nonsustained ventricular tachycardia were detected on a 48 h electrocardiogram. Cardiac magnetic resonance imaging showed increased thickness of the septum (39.3 mm) and the apex of the right ventricle, as well as massive delayed enhancement at the hypertrophied septum and apex. Based on the extreme LV hypertrophy and the abnormal blood pressure response during exercise, cardioverter defibrillator implantation was recommended for primary prevention of sudden death. HCM involving the right ventricular apex is rare, and cardiac magnetic resonance imaging is the imaging modality of choice for diagnosis. Four-chamber gradient echo sequence (Figure 1A), short-axis, T1-weighted spin echo sequence (Figure 1B) and four-chamber delayed enhancement imaging (Figure 1C) showed increased thickness of the septum and the apex of the right ventricle, as well as massive enhancement (bright signal) at the hypertrophied septum and apex. Figure 1) Increased thickness of septum and the apex of the right ventricle (RV) shown by four-chamber gradient echo sequence (A), short-axis, T1-weighted spin echo sequence (B) and four-chamber delayed enhancement imaging, demonstrating massive enhancement at ...

Anestesia para cesariana em paciente portadora de cardiomiopatia hipertrófica familiar: relato de caso

Familiar Hypertrophic cardiomyopathy (FHC) is a rare hereditary cardiac disorder characterized by hypertrophy of the ventricular septum and variable degrees of subvalvular aortic stenosis. In this disease, the increase in myocardial contractility and reduction in peripheral vascular resistance can aggravate left ventricular outlet obstruction, leading to arrhythmias and cardiac ischemia. The objective of this report was to discuss the anesthetic management of cesarean section in a patient with FHC. A patient in the 33rd week of pregnancy and prior diagnosis of FHC presented, on the 24-hour Holter monitor, 22 episodes of non-sustained ventricular tachycardia (NSVT) and 2 episodes of sustained ventricular tachycardia (SVT). She complained of episodes of palpitation, dyspnea, and chest pain of short duration. The patient was medicated with atenolol, with control of symptoms and cardiac arrhythmias. Within 38 weeks and 5 days of gestation, the patient underwent elective cesarean section. Besides the usual monitoring, analysis of the ST segment and invasive blood pressure were also instituted. Anesthesia consisted of combined spinal-epidural technique with subarachnoidal administration of 5 microg of sufentanil followed by the administration of increasing doses of 0.375% bupivacaine until it reached the level of T6 (total of 16 mL). Metaraminol was used as a vasopressor. Perioperative maternal hypotension or other complications were not observed. General anesthesia is often used for cesarean sections in patients with FHC. Spinal-epidural anesthesia with slow installation of the blockade was a safe alternative. In those patients, one should avoid an increase in myocardial contractility and, if necessary, a a-agonist should be used to treat maternal hypotension.

Coronary Slow Flow Phenomenon and Risk for Sudden Cardiac Death Due to Ventricular Arrhythmias: A Case Report and Review of Literature

We report a case of coronary slow flow phenomenon (CSFP) in a patient who underwent coronary angiography due to anginal chest pain and recurrent syncope with complete normalization of flow after intracoronary adenosine. He was noted to have multiple episodes of nonsustained ventricular tachycardia on holter monitor and increased QTc dispersion on surface electrocardiogram (EKG). He responded very well to oral dipyridamole therapy with complete resolution of his symptoms and no episodes of ventricular tachycardia on the event recorder at 3 months. We review the diagnosis and clinical features of CSFP and its association with increased QTc dispersion and the role of oral dipyridamole therapy in this condition.

Ventricular arrhythmias following intracoronary bone marrow stem cell transplantation

We describe the appearance of delayed episodes of ventricular arrhythmias in 4 patients out of 72 undergoing intracoronary transplantation of autologous bone marrow mononuclear cells (BMMC) following ST elevated myocardial infarction (STEMI). Two cases with severely depressed systolic function presented electrical storms with monomorphic sustained ventricular tachycardia (SVT) within 2 to 3 days following cell transplantation, even though there were no periprocedural complications. Both patients were implanted with an internal defibrillator (ICD) after ruling out coronary re-occlusion. The remaining 2 patients presented several asymptomatic episodes of non-sustained ventricular tachycardia within one month following cell transfer. Only one of the latter presented syncopal SVT through programmed ventricular stimulation, undergoing ICD implantation afterwards. Neither new arrhythmic episodes nor ICD interventions have occurred during later follow-up of the three ICD patients (639+/-59 days). Information from large multicenter databases and our historical cohort of STEMI patients indicates that the rate of VT occurring within the first weeks after the initial 48 hours of infarction is significantly lower than that observed in our cell-therapy experience. The lack of information regarding the appearance of malignant arrhythmias in patients with severe systolic dysfunction following this type of therapy after STEMI requires us to be extremely cautious. However, any claim of a mechanism related to cell transfer would be completely speculative with the available data. Therefore, our only aim when reporting our findings is to recommend a short but longer stay (2-3 days) following cell transplantation, particularly in patients with a natural tendency to develop arrhythmic events.

A memorable experience

The electrocardiographic phenomenon of cardiac memory results from aberrant ventricular activation and causes transient ECG features that can mimic ischaemia. We present the case of a patient with ischaemic cardiomyopathy who exhibited evidence of T-wave memory in the setting of multiple episodes of non-sustained ventricular tachycardia that were triggered by an insect bite.

Acute myocardial infarction during a dobutamine stress echocardiography, in a patient with angiographically normal coronaries

We report a case of acute myocardial infarction during a dobutamine stress echo (DSE) study in a middle age man. Our patient experienced a severe crushing retrosternal pain at peak DSE study, at the time the ECG recorded an episode of non-sustained ventricular tachycardia followed by a persistent significant ST segment elevation in V2–V6 leads. Symptoms and ECG findings remained despite the use of intravenous (IV) nitrates and therefore thrombolysis was given. A subsequent coronary angiogram revealed only mild atheromatous changes but no stenosis.