Paweł Ptaszyński

Metoprolol succinate vs. ivabradine in the treatment of inappropriate sinus tachycardia in patients unresponsive to previous pharmacological therapy

AIMS Inappropriate sinus tachycardia (IST) is a clinical syndrome characterized by excessive resting heart rate (HR) or disproportional increasing HR during exercise. The treatment of IST symptoms using beta-blockers or calcium channel-blockers is often non-effective or not well tolerated. Ivabradine is a new agent inhibiting sinus node I(f) current, resulting in a decrease of HR without haemodynamic compromise. METHODS AND RESULTS We enrolled 20 patients (36 ± 10 years; 14 women) affected by IST and resistant to previous administered therapy by using beta-blockers or verapamil. After 4 weeks of treatment with metoprolol succinate (up to 190 mg once a day) the therapy was switched to ivabradine up to 7.5 mg twice daily. Holter monitoring and treadmill stress test were performed after 1 and 2 months following start of the study. We observed a significant reduction of resting HR both for metoprolol and for ivabradine compared with baseline (92.8 vs. 90.2 vs. 114.3 b.p.m.; P< 0.001). During daily activity there was an even larger decrease of HR on ivabradine (mean daytime HR 94.6 vs. 87.1 vs. 107.3 b.p.m.; P< 0.001). Ivabradine was very well tolerated whereas in 10 patients on metoprolol we observed hypotension or bradycardia requiring dose reduction. Significantly lower incidence of IST-related symptoms were registered on ivabradine therapy than on metoprolol. Fourteen patients (70%) treated with I(f) blocker were free of IST-related complaints. CONCLUSIONS Metoprolol and ivabradine exert a similar effect on resting HR in patients with IST. Ivabradine seems to be more effective to relieve symptoms during exercise or daily activity.

Ivabradine in Combination With Metoprolol Succinate in the Treatment of Inappropriate Sinus Tachycardia

Background: Inappropriate sinus tachycardia (IST) is a clinical syndrome characterized by excessive resting heart rate (HR) or a disproportional increase in HR during exercise. β-blocker or calcium channel-blocker therapy is often noneffective or not well tolerated. The HR reduction on ivabradine is similar to β-blockers but in some patients its efficacy to resolve all IST-related symptoms is limited. The aim of the study was to assess the efficacy and safety of combining ivabradine with metoprolol succinate in patients with refractory highly symptomatic IST. Methods: Twenty patients (36 ± 10 years; 16 women) with IST were enrolled. All patients received metoprolol succinate 95 mg single dose during the first month of the study. After 4 weeks of treatment with metoprolol, ivabradine was administered as adjuvant therapy up to 7.5 mg twice daily. Holter monitoring and treadmill stress test were performed at baseline, after 4, and 8 weeks of the study, respectively. Results: We observed significant and similar reduction in resting HR both for metoprolol and for combined therapy compared to the baseline. The mean HR during daily activity was significantly lower on ivabradine and metoprolol compared to monotherapy with β-blocker. The combined treatment yielded a significant increase in exercise capacity as assessed by treadmill stress test. After 4 weeks of combined therapy a significant reduction in IST-related symptoms, measured by means of the European Heart Rhythm Association score, was observed. Conclusion: Combining ivabradine with metoprolol is an effective and well-tolerated treatment option for IST in patients with refractory to monotherapy.

Cryoablation for treatment of cardiac arrhythmias: results of the European Heart Rhythm Association survey

&NA; The purpose of this survey was to assess the current practice in Europe regarding cryoablation for treatment of different cardiac arrhythmias. The data are based on an electronic questionnaire sent to members of the European Heart Rhythm Association Research Network. Responses were received from 49 centres in 18 countries. The results show that cryoablation for supraventricular tachycardia in European centres is an alternative to radiofrequency ablation, which is in accordance with guidelines. There is reasonable consensus regarding clinical results and complications of cryoablation procedure. Some inter‐centre variability with respect to patient selection and ablation strategy in cryoablation of atrial fibrillation was demonstrated, underscoring the need for further research.

Inflammation and arrhythmias: potential mechanisms and clinical implications

Inflammation is a pathological condition known since ancient times. Recent discoveries of inflammatory markers have given new insights into the role of inflammation in the pathogenesis of arrhythmias. This article reviews global data on possible correlations between inflammation – acute or chronic – and cardiac arrhythmias. The authors discuss the role of inflammation in patients with supraventricular and ventricular arrhythmias. Collected data support the hypothesis that the inflammatory process may be an important factor in cardiac rhythm disturbances.

A New Type of Dual Atrioventricular Nodal Nonreentrant Tachycardia

Dual atrioventricular nodal nonreentrant tachycardia (DAVNNT) is very rarely observed clinically. The first review of this arrhythmia was published in 2011 by Wang, where four types of DAVNNT were described. Our case report presents a phenomenon that has never been published before. We revealed a very specific sequence of double fire phenomenon, 1:1 atrioventricular (AV) conduction and AV block.

Abnormal filter setting or Brugada syndrome

26-year old patient was admitted to our department with suspected Brugada syndrome (BrS). He complained of recurrent dizziness due to which he was taken by a team of rescuers to the district hospital, where the recorded ECG demonstrated isolated 3–7 mm ST segment elevation in leads V1–V3. Coronary angiography performed in this hospital was normal. Then patient was transferred to our department for consideration of ICD implantation. ECG registration in our hospital with 0.05 Hz (3.2 s) filter showed sinus bradycardia with 1–2 mm ST segment elevation in precordial leads. A detailed analysis of all ECGs proved that the district hospital ECG was performed in manual mode with the application of 1.5 Hz (0.1 s) low frequency high-pass filter. To confirm the effect of incorrect filter as the cause of misdiagnosis we repeated ECG recording using the recorder which allows to apply the same settings 1.5 Hz (0.1 s) as in district hospital and reconstructed ECG with repolarisation abnormalities. Negative ajmaline test (1 mg/kg) additionally reaffirmed an exclusion of dynamic form of BrS.

The clinical value of T-wave alternans derived from Holter monitoring

Microvolt-level T-wave alternans (TWA) assessed by spectral method during an exercise stress test has been widely studied for risk stratification. Several studies have documented the association of a positive TWA with total mortality and arrhythmic events. Nevertheless, the need to achieve an elevated and stabilized heart rate resulting in a considerable proportion of indeterminate test results constitutes one of the main limitations of this method. It is well recognized that arrhythmic events may be triggered not only by physical but also by mental stress and are not necessarily associated with exercise. Detection of TWA in ambulatory electrocardiogram recordings during daily activities might be a valuable option in risk stratification. This review describes the modified moving average (MMA) technique for detection of TWA and summarizes the results of clinical studies on the prognostic value of MMA-TWA. So far, MMA-TWA has been studied in over 5000 patients including those evaluated during exercise as well as during daily activities with ambulatory ECG recordings. The results of these studies indicate that increased MMA-TWA is associated with higher risk of cardiac mortality and arrhythmic events.

Atypical position of subcutaneus implantable cardioverter-defibrillator as a solution in hypertrophic cardiomyopathy patient with initially negative electrocardiographic screening

A 35-year-old female with hypertrophic cardiomyopathy was admitted due to malfunction of an implantable cardioverter-defibrillator (ICD). The device was implanted 9 years ago after successfully resuscitated ventricular fibrillation (VF). A failure of a defibrillation lead, probably due to crush syndrome, was diagnosed. Additionally, an occlusion of the left subclavian vein was revealed. As the patient refused an extraction of the lead with reimplantation of the ICD, a subcutaneous implantable cardioverter-defibrillator (S-ICD) was proposed as an alternative option. An electrocardiographic (ECG) screening disclosed that none of …

Renal denervation--hypes and hopes.

Catheter-based renal denervation (RDN) is a novel invasive approach in the treatment of resistant hypertension. It is considered a minimally invasive and safe procedure which, as shown by initial experimental and clinical trials, is able not only to reduce blood pressure but also to modify its risk factors by modulation of autonomic nervous system. Recently published results of a randomized Symplicity HTN-3 trial, which failed to demonstrate RDN-induced reduction of blood pressure at six months, decreased the initial enthusiasm regarding RDN and raised a question about real efficacy of this procedure. Nevertheless, still there are some other conditions characterized by increased sympathetic tone such as heart failure, atrial fibrillation, or ventricular arrhythmias that may benefit from RDN. Furthermore, novel therapeutical approach toward RDN using adapted electrophysiological or new specially designed electrodes may improve effectiveness of RDN procedure.

Risk-benefit assessment of ivabradine in the treatment of chronic heart failure

Heart rate is not only a major risk marker in heart failure but also a general risk marker. Within the last few years, it has been demonstrated that reduction of resting heart rate to <70 bpm is of significant benefit for patients with heart failure, especially those with impaired left ventricular systolic function. Ivabradine is the first innovative drug synthesized to reduce heart rate. It selectively and specifically inhibits the pacemaker If ionic current, which reduces cardiac pacemaker activity. Therefore, the main effect of ivabradine therapy is a substantial lowering of heart rate. Ivabradine does not influence intracardiac conduction, contractility, or ventricular repolarization. According to the European Society of Cardiology guidelines, ivabradine should be considered in symptomatic patients (New York Heart Association functional class II–IV) with sinus rhythm, left ventricular ejection fraction ≤35%, and heart rate ≥70 bpm despite optimal treatment with a beta-blocker, angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, and a mineralocorticoid receptor antagonist. As shown in numerous clinical studies, ivabradine improves clinical outcomes and quality of life and reduces the risk of death from heart failure or cardiovascular causes. Treatment with ivabradine is very well tolerated and safe, even at maximal recommended doses.