Pulmonary arterial hypertension (PAH) is a clinical condition characterized by the presence of pre-capillary PH and pulmonary vascular resistance >3 UW, in the absence of other causes of pre-capillary PH [1]. Despite the availability over the past 20 years of multiple drugs, PAH prognosis is still poor with a median survival of 7 years [2]. As a rare disease the European Union encourages research and gives priority founding on this field [3]. Our Center is currently one of the two most important Italian centers for PAH [4]. Risk stratification in PAH is challenging; as in the most relevant and international registers, more than 80% of all patients with PAH are allocated at the intermediate and high risk with a variable treatment response and a different mortality rate [5-8]. Palpitation, syncope and sudden cardiac death are frequent findings in PAH patients and could be related to arrhythmias originating from the right heart [9-13]. As widely reported, arrhythmias confer a substantial risk of mortality and morbidity increasing risk of hospitalizations and clinical worsening. Nevertheless, cardiac arrhythmia in PAH has not yet well investigated and requires further investigation [14].
Aim of our study is to detect arrhythmias occurring in PAH patients with rhythm disorders in medical history, in order to better understand the pathophysiologic substrate. We¿ll conduct an observational and prospective study enrolling 30 consecutive PAH patients with palpitations, tachycardia or syncope in medical history. An electrophysiology study (EPS) will be performed during the routinely right heart catheterization. A voltage analysis and a conduction analysis will be performed in order to detect areas of electrical instability potentially determining arrhythmias. Researching on arrhythmias as a new feature on PAH and then finding out fatal or less severe arrhythmias can to better stratify the risk in PAH especially at the intermediate risk and helping the patients¿ management.
Despite the availability over the past 20 years of multiple drugs, pulmonary arterial hypertension (PAH) remains a severe clinical condition [1]. Assessing the prognosis is an important part of care of patients with PAH and includes clinical, functional, exercise, non-invasive and invasive variables. One of the main limitation of the existing scores is that above 70% of the patients is at intermediate risk and that, despite the same risk profile, patients show an heterogenous treatment response and mortality rate. [2-5].
Sudden cardiac death is reported till 25% of death in PAH, nevertheless there is still a gap on the mechanism concerning about the involved arrhythmic substrate.
Arrhythmias in PAH patients are still not so well investigated and characterized, in fact in literature there are few studies about arrhythmias in PAH patients and mostly not conclusive for clinical decision [6-9].
Researching on new PAH aspects as arrhythmias could improve patients¿ management, helping clinicians to understand other potential causes of clinical worsening and death in PAH. In this way, clinicians could also improve the current PAH risk stratification scores, especially for patients allocated at intermediate risk.
Aim of the present study is to identify arrhythmias occurring in PAH patients, to analyze their electrophysiological substrate, to correlate them to clinical worsening and finally to establish their influence on PAH patients¿ outcome.
Considering the greater sensitivity and specificity compared to other tests such as 24h-ECG or loop-recorder [10-11], we will perform an electrophysiological study (EPS) in patients with PAH who present in the history symptoms such as palpitations or syncope or unexplained tachycardia. Indeed, EPS is a useful tool in the evaluation of patients with cardiac arrhythmias and conduction disorders, both for diagnosis and treatment, allowing to perform ablation in the same session. Considering that arrhythmias with their hemodynamic effects could be the cause of RV failure and of PAH patients¿ hospitalizations.
Finally researching on this new feature on PAH and then finding out fatal or less severe arrhythmias can to better stratify the risk of patients especially at the intermediate risk adding an important contribute to the PAH patients¿ management.