Continuous long-term heart rate variability and risk assessment in pulmonary hypertension.

OBJECTIVE: Current multimodal risk assessment for pulmonary hypertension (PH) has been redefined with a simplified assessment for follow-up in the new European Society of Cardiology/European Respiratory Society (ESC/ERS) guidelines. Follow-up risk assessment parameters include WHO functional class, 6 min walk test and N-terminal pro-brain natriuretic peptide. Although these parameters have prognostic implications assessment reflect data relating to specific time points. METHODS: Patients diagnosed with PH received an implantable loop recorder (ILR) to monitor daytime and night-time heart rate (HR), HR variability (HRV) and daily physical activity. Associations between the ILR measurements and established risk parameters were analysed using correlations, linear mixed models as well as logistical mixed models for addressing the ESC/ERS risk-score. RESULTS: 41 patients (median age: 56 years, range: 44-61.5 years) were included. Continuous monitoring had a median duration of 755 days (range: 343-1138 days), totalling 96 patient-years. In the linear mixed models, HRV and physical activity indexed by daytime HR (PAiHR) were significantly associated with the ERS/ERC risk parameters. In a logistical mixed model, HRV revealed a significant difference between 1-year mortality (<5% vs >5%) (p=0.027) with an OR of 0.82 for being in the group with 1-year mortality >5% for every increase by one HRV unit. CONCLUSIONS: Risk assessment in PH can be refined with continuous monitoring of HRV and PAiHR. These markers were associated with the ESC/ERC parameters. Our study with continuous risk stratification in PH demonstrated that a lower HRV predict worse prognosis.

Continuous cardiac monitoring in a patient with terminal pulmonary hypertension and eventual bilateral lung transplantation.

As pulmonary arterial hypertension (PAH) progress, arrhythmias are becoming an increasingly prominent phenomenon. Supraventricular tachycardias have been shown to have an incidence of up to 35% in pulmonary hypertension.Continuous cardiac monitoring was deployed in a patient with severe PAH 100 days before bilateral lung transplantation (BLTX). Despite being graded as WHO functional class IV, no arrhythmias were observed before BLTX. Furthermore, the case describes clinical improvement, along with a significant increase in heart rate variability (HRV) and decrease in night-time heart rate in the post-transplantation period.No arrhythmias were observed preoperatively during continuous monitoring in a 100-day period despite the patient's intrinsically high risk for arrhythmias. Increasing HRV and lower resting heart rate were observed after BLTX. Since these parameters correlate with the clinical condition, they might be valuable in risk assessment in patients with pulmonary hypertension.

Assessment of cardiac arrhythmias using long-term continuous monitoring in patients with pulmonary hypertension.

BACKGROUND: Cardiac arrhythmias are considered a prominent phenomenon in patients with pulmonary hypertension (PH). Older studies reported that 8% to 35% of patients with PH had supraventricular tachycardia (SVT), associated with adverse outcomes. Still, these arrhythmias have only been investigated via short-term monitoring or limited electrocardiogram recordings. METHODS: Patients without previous arrhythmias diagnosed with PH at a tertiary facility received an insertable cardiac monitor as part of a prospective cohort study. Baseline assessments included World Health Organization functional class, six-minute walk test, echocardiography, and cardiac magnetic resonance imaging. RESULTS: Thirty-four patients with PH were included. Twenty-four patients had pulmonary arterial hypertension (PAH) and 10 had chronic thromboembolic PH (CTEPH). During 46 patient-years of continuous monitoring (median: 594 (range: 334-654) days per patient), 70 arrhythmia episodes were recorded in 13 patients (38%), with a median of two (range: 1-3) episodes and an arrhythmic burden median of 1.6 (range: 0.1-228) minutes per patient. SVTs were the most common arrhythmias, with 16% of episodes being atrial fibrillation and 84% being other types of SVTs. Additionally, three patients experienced bradycardias, including one resulting in syncope and subsequent pacemaker implantation. None of the patients had sustained ventricular arrhythmias. CONCLUSIONS: Arrhythmias were seen in 38% of contemporary patients with PH during long-term continuous monitoring; however, the vast majority of episodes were short and self-limiting. Modern therapy may alleviate the development of arrhythmias in stable patients with PH. This study is the first study to deploy long-term continuous monitoring in patients with PH.