Editorial 4TH issue CCE

Abstract

The 4th issue of CCE is dedicated on Arrhythmias. Rhythm disturbances often scare junior and sometimes senior Cardiologists. There has been tremendous progress on the diagnosis, treatment, and follow-up of arrhythmia patients. Old recording techniques, such as the ECG, still remain contemporary and valuable tools for the initial assessment and diagnosis. Novel, sophisticated non-invasive diagnostic techniques and invasive mapping systems have been developed over the last 20 years, allowing further understanding of arrhythmia mechanisms, precise diagnosis, and thus effective and successful treatment. The widespread utilization of radiofrequency ablation and the development of modern cardiac rhythm management devices in the late 80s and 90s are cornerstone treatments for the cure of tachyarrhythmias and the prevention of sudden cardiac death, which in turn exploded Invasive Electrophysiology.

In the current issue, Dr Katritsis reviews an old, but always important and current issue: The differential diagnosis of supraventricular tachycardias (SVT) from the surface ECG and during electrophysiology study. In the first part of the paper, he refers to the important “tips and tricks” of how to diagnose the type of SVT from the surface 12-lead ECG, i.e., the identification and the chronic relation of retrograde P waves to the QRS. In the second part, he reviews all the important electrophysiologic maneuvers required for the establishment of the diagnosis.

In the succeeding two papers, Drs Arsenos, Sideris, and Gatzoulis are reviewing the risk-stratification methods for the primary prevention of arrhythmic sudden cardiac death (SCD) in post-infarction patients, a very common clinical issue in everyday practice. Implanted cardioverter defibrillator (ICD) is undoubtfully a life-saving and effective therapy for the prevention of SCD, both for primary and secondary prevention of post-myocardial infarction (MI) patients 1. Still in 2016, the most important prognostic marker remains the left ventricular ejection fraction (EF), leaving a big “gray-zone” area of patients, who may not utilize this complicated treatment during their lives. In both papers, they review the pros and cons of the available non-invasive and invasive techniques, and in their second paper they review a “hot” and unanswered issue: the risk stratification of post-MI patients with a preserved EF. The value of a combination of non-invasive risk markers (late potentials, T-wave alternans, heart rate variability and turbulence, deceleration capacity) with invasive ventricular stimulation methods is the subject of the ongoing PRESERVE-EF trial 2. The later and similar trials are listed in order to elucidate the magnitude of the problem.

Atrial fibrillation is the most common supraventricular tachyarrhythmia, affecting more than 5 million in Europe. Pharmacologic treatment with antiarrhythmic drugs is of limited efficacy and is associated with high recurrence rates and is some case with proarrhythmic effects 3. Drs Frangakis and Vassilikos refer to the agents with selective affinity to ion channels specifically or predominately involved in the atrium. Vernakalant and ranolazine are predominantly ‘atrial-selective’ blockers, dronedarone is considered as a ‘multi-channel blocker’. Ion-channel modulation, abnormal Ca2+ handling and structural remodeling provide a wide range of promising therapeutic targets expecting to facilitate the development of drugs with improved safety and efficacy. Atrial fibrillation ablation is a potent treatment, which has been criticized, but has been proposed as class I alternative to pharmacological therapy in the recent Guidelines 4. Drs Vlachos and Efraimidis provide an extensive review of the available techniques and results. Invasive techniques, despite a 4.5% incidence of complications, have been shown to be superior to drug treatment, regarding long-term success and quality of life improvement 5.

Cardiovascular implantable electronic devices (CIEDs) use has been increased significantly over the last decade due to expanding indications (biventricular devices and prophylactic use of ICDs), and to increased needs due to the aging of the population. There are several issues with this population of patients. Among the possible complications, infection is a relatively rare, but serious and cumbersome event, which may even lead to endocarditis. Drs Manolis and Melita in their paper regarding the management of infected CRMs, stress the need of total removal of the system in the majority of the cases as the optimum treatment. The removal of the electrodes using special techniques should be done in experienced centers to reduce complications and increase success rate.

Biventricular pacing is a well-established treatment for heart failure patients who are on optimal medical treatment and present with left ventricular ejection fraction <35% and broad QRS (>120 msec). Despite the technical improvements, about a third of these patients do not show any significant improvement, or gradually deteriorate despite the initial success. These devices are complex in their programming, and in order to gain the maximum benefit out of this therapy, there are standard steps which are mandatory and must be followed in an organized fashion. Drs Theofilogiannakos and Vassilikos in their paper entitled “How to follow a patient with heart failure and a biventricular device”, address the necessary checkpoints in which the clinician should focus on during follow-up in order to optimize the performance of these devices. These include the clinical, radiographical, and biochemical profile evaluation of the patient, the paced ECG pattern, the percentage of true biventricular pacing, the presence of arrhythmias, and the optimization using echocardiography or intracardiac electrograms.

All current CIEDs have the capability of remote monitoring (RM) over telephone lines or mobile networks, and this modality is recommended in the practice guidelines 6. This function, as expected, has shown to reduce office visits and improve arrhythmia or device malfunction detection. On the other hand, there is a debate about the improved clinical outcomes, and the legal and economical issues related to this technology. Drs Deftereos et al. address all these issues in their paper entitled: Remote monitoring of the cardiac rhythm: where do we stand today? In addition, Dr Varma in his paper further examines how RM is incorporated into the current updated practice guidelines, and to what extent it has been implemented in health care systems, and how this modality is going to change the clinical workflow.

There are limited data regarding the management of CIED patients presenting for elective generator replacements. Patients’ status and comorbidity are dynamic and may change significantly over their life span, thus affecting the initial indications for ICD or CRT implantation at the time of presentation. Drs Kallergis et al. review the practical and ethical issues of upgrading or downgrading a CIED at the time of generator replacement, taking into account cost-effectiveness, new risk stratification parameters at the time of replacement, patients’ preference and physician's experience.

Finally Dr Koratzopoulos presents a case of prolonged bradycardia detected by an implantable loop recorder.

Dr. Vassilikos has nothing to disclose.