Practical ways to reduce radiation dose for patients and staff during device implantations and electrophysiological procedures.

Despite the advent of non-fluoroscopic technology, fluoroscopy remains the cornerstone of imaging in most interventional electrophysiological procedures, from diagnostic studies over ablation interventions to device implantation. Moreover, many patients receive additional X-ray imaging, such as cardiac computed tomography and others. More and more complex procedures have the risk to increase the radiation exposure, both for the patients and the operators. The professional lifetime attributable excess cancer risk may be around 1 in 100 for the operators, the same as for a patient undergoing repetitive complex procedures. Moreover, recent reports have also hinted at an excess risk of brain tumours among interventional cardiologists. Apart from evaluating the need for and justifying the use of radiation to assist their procedures, physicians have to continuously explore ways to reduce the radiation exposure. After an introduction on how to quantify the radiation exposure and defining its current magnitude in electrophysiology compared with the other sources of radiation, this position paper wants to offer some very practical advice on how to reduce exposure to patients and staff. The text describes how customization of the X-ray system, workflow adaptations, and shielding measures can be implemented in the cath lab. The potential and the pitfalls of different non-fluoroscopic guiding technologies are discussed. Finally, we suggest further improvements that can be implemented by both the physicians and the industry in the future. We are confident that these suggestions are able to reduce patient and operator exposure by more than an order of magnitude, and therefore think that these recommendations are worth reading and implementing by any electrophysiological operator in the field.

A reappraisal on lidocaine-sensitive repetitive, uniform atrial tachycardia.

BACKGROUND: Lidocaine sensitive, repetitive atrial tachycardia is an unusual arrhythmia whose electrophysiologic substrate remains undefined. We aimed to analyze the electropharmacologic characteristics of this arrhythmia with emphasis on its cellular substrate and response to drug challenges. METHODS: We retrospectively analyzed a series of 18 patients from an electrocardiographic and electrophysiologic perspective and the response to pharmacological challenge. RESULTS: There was no evidence of structural heart disease in 12 patients, 4 patients presented with systemic hypertension; one patient had a prior myocardial infarction and one a mitral valve prolapse. The arrhythmia depicted a consistent pattern in nine patients. The first initiating ectopic beat showed a long coupling interval, the cycle length of the second atrial ectopic beat presented the shortest cycle length and a further prolongation was apparent towards the end of the atrial salvos. Conversely, in the other nine cases, the atrial tachycardia cycle length was erratic. The arrhythmia was suppressed by asynchronous atrial pacing at cycle lengths longer than those of the atrial tachycardia. Intravenous lidocaine eliminated the arrhythmia in all patients, but intravenous verapamil suppressed the atrial tachycardia in only two patients while adenosine caused a transient disappearance in 2/8 patients. Only one patient responded to all the three agents. Radiofrequency ablation was successfully performed in 10 patients. CONCLUSIONS: Repetitive uniform atrial tachycardia can be sensitive to lidocaine. In few cases, this rare focal arrhythmia may be also suppressed by adenosine and/or verapamil, which suggests a diversity of electrophysiologic substrates that deserve to be accurately identified.

Inappropriate sinus tachycardia: current therapeutic options.

Inappropriate sinus tachycardia (IST) is an uncommon form of arrhythmia characterized by an increased heart rate that is out of proportion to a normal physiologic demand. The etiology of IST remains ill-defined and controversial. Clinical presentation of IST is highly variable, from isolated to sustained palpitations, and can cause deterioration in one's quality of life. IST is usually a diagnosis of exclusion and it is important to rule out other causes of sinus tachycardia before reaching a final diagnosis. Evaluation of cardiac autonomic reflex function is essential to support the diagnosis of IST. The treatment of IST aims to target the multiple mechanisms involved in this disease, and multidisciplinary management, including cardiac rehabilitation, pharmacotherapy, and occasionally radiofrequency modification of the sinus node, should be considered. The prognosis is usually benign, although regular follow-up is required to optimize therapy and prevent the onset of tachycardiomyopathy.