Ventricular tachycardias in patients with pulmonary hypertension: an underestimated prevalence? A prospective clinical study

Bradycardias in Patients with Pulmonary Hypertension-Prevalence, Pathophysiology and Clinical Relevance

INTRODUCTION

Arrhythmias are a frequent complication of pulmonary hypertension (PH). Supraventricular tachycardias (SVT) are predominantly reported and are associated with clinical deterioration and an increased mortality. In contrast, the prevalence and clinical relevance of bradycardias is largely unclear. Therefore, the aim of the present study was to determine a prevalence of bradycardias in PH patients and to outline their clinical relevance.

MATERIAL AND METHODS

Between January 2000 and June 2013, consecutive PH patients were pro- and retrospectively enrolled in two cohorts. Patients received either a 24 h or 72 h Holter ECG.

RESULTS

A total of 314 patients (58% female, mean age: 63 years) from PH groups 1-5 (39%, 11%, 19%, 28%, 3%) were included. Basic heart rhythm was sinus rhythm in 87% of patients (9% atrial fibrillation, 2% atrial flutter and 2% paced rhythm). Further arrhythmias were detected in 34% of patients (SVT: 12%, non-sustained ventricular tachycardia: 16%) with a 6% prevalence of relevant bradycardias. Atrioventricular block was revealed in 5% of patients (seven first-degree, one and three second-degree Wenckebach and Mobitz type, respectively, four third-degree), and 1% revealed sinoatrial block (one second-degree, third-degree and unspecified each).

CONCLUSIONS

The prevalence of bradycardias appears to be about 5-10% in PH patients. Most of them are short and self-limiting. However, some patients experience syncope or clinical deterioration and, therefore, need specific treatment. To find these patients, long-term ECG monitoring combined with ECG-symptom correlation may be useful. Bradycardic medication should be excluded as a cause.

In-hospital outcomes of cardiac tamponade in patients with pulmonary hypertension: A contemporary analysis

BACKGROUND

Cardiac tamponade (CT) has an atypical presentation in patients with underlying pulmonary hypertension (PH). Evidence regarding the impact of PH on CT in-hospital outcomes is lacking.

METHODS

We used the National Inpatient Sample database to identify adult hospitalizations with a diagnosis of CT between 2016 and 2020, using relevant ICD-10 diagnostic codes. Baseline characteristics and in-hospital outcomes were compared in patients with and without a PH. Multivariate logistic regression analyses and case-control matching were performed, adjusting for age, race, gender, and statistically significant co-morbidities between cohorts.

RESULTS

A total of 110,285 inpatients with CT were included, of which 8,670 had PH. Patients with PH tended to be older (66 ± 15.7) and female (52.5%), had significantly higher rates of hypertension (74% vs 65%), CAD (36.9% vs. 29.6%), CKD (39% vs 23%), DM (32.1%, vs. 26.9%), chronic heart failure (19.0% vs 9.7%) and COPD (26% vs 18%)(P<0.001 for all). After multivariate logistic regression, PH was associated with higher all-cause mortality (aOR 1.29; 95% CI: 1.11-1.49), higher rates of cardiogenic shock (aOR: 1.19; 95% CI: 1.01-1.41), ventricular arrythmias (aOR: 1.63; 95% CI: 1.33-2.01), longer length of stay (11 days vs 15 days), and higher total hospitalization costs ($228,314 vs $327,429) in patients presenting with CT. Despite pericardiocentesis being associated with lower in-hospital mortality, patients with PH were less likely to undergo pericardiocentesis (aOR: 0.77; 95% CI: 0.69-0.86).

CONCLUSION

PH was associated to increased in-hospital mortality and a higher rate of cardiovascular complications in an inpatient population with CT. Pericardiocentesis was associated with reduced mortality in patients with CT, regardless of whether they had PH. However, patients with PH underwent pericardiocentesis less frequently than those without PH.

Sudden cardiac death in pulmonary arterial hypertension

Pulmonary arterial Hypertension (PAH) is a progressive disease marked by significant morbidity and mortality due to pulmonary vasculopathy and right ventricular (RV) dysfunction. Despite advances in PAH medical therapies which have improved clinical outcomes and survival, patients continue to face severe complications, including a notable incidence of sudden cardiac death (SCD). The high arrhythmic burden, coupled with mechanical complications such as left main compression syndrome, pulmonary artery dissection, rupture, and severe hemoptysis, significantly contribute to the risk of SCD. Close monitoring and a meticulous diagnostic approach are essential for risk stratification and timely intervention, aiming to mitigate the risk of premature death in these patients. The aim of this review is to provide a comprehensive understanding of these risks and highlight strategies for improving patient outcomes through early identification, prevention and effective management.

Cardiac Arrhythmias in Pulmonary Arterial Hypertension and Chronic Thromboembolic Pulmonary Hypertension: Mechanistic Insights, Pathophysiology, and Outcomes

Arrhythmias are increasingly recognized as severe complications of precapillary pulmonary hypertension, encompassing pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH). Despite their significant contribution to symptoms, morbidity, in-hospital mortality, and potentially sudden death in PAH/CTEPH, there remains a lack of comprehensive data on epidemiology, pathophysiology, and outcomes to inform the management of these patients. This review provides an overview of the latest evidence on this subject, spanning from the molecular mechanisms underlying arrhythmias in the hypertrophied or failing right heart to the clinical aspects of epidemiology, diagnosis, and treatment.

Incidence and prognostic significance of malignant arrhythmias during (repetitive) Holter electrocardiograms in patients with pulmonary hypertension

Background

In patients with pulmonary hypertension (PH), increased pulmonary vascular resistance (PVR) may lead to increased right ventricular afterload and cardiac remodelling, potentially providing the substrate for ventricular arrhythmias. Studies dealing with long term monitoring of patients with PH are rare. The present study evaluated the incidence and the types of arrhythmias retrospectively recorded by Holter ECG in patients with newly detected PH during a long-term Holter ECG follow-up. Moreover, their impact on patient survival was evaluated.

Patients and methods

Medical records were screened for demographic data, aetiology of PH, incidence of coronary heart disease, level of brain natriuretic peptide (BNP), results from Holter ECG monitoring, 6-minute walk test distance, echocardiographic data and hemodynamic data derived from right heart catheterization. Two subgroups were analyzed: 1. patients (n = 65) with PH (group 1 + 4) and derivation of at least 1 Holter ECG within 12 months from initial detection of PH and 2. patients (all PH etiologies, n = 59) with 3 follow-up Holter ECGs. The frequency and complexity of premature ventricular contractions (PVC) was classified into "lower" and "higher" (=non sustained ventricular tachycardia, nsVT) burden.

Results

Holter ECG revealed sinus rhythm (SR) in most of the patients (n = 60). Incidence of atrial fibrillation (AFib) was low (n = 4). Patients with premature atrial contractions (PAC) tend to have a shorter period of survival (p = 0.098), PVC were not correlated with significant survival differences. During follow-up PAC and PVC were common in all PH groups. Holter ECG revealed non sustained ventricular tachycardia in 19/59 patients [(32.2%); n = 6 during first Holter-ECG, n = 13 during second/third Holter-ECG]. In all patients suffering from nsVT during follow-up previous Holter ECG revealed multiform/repetitive PVC. PVC burden was not linked to differences in systolic pulmonary arterial pressure, right atrial pressure, brain natriuretic peptide and results of six-minute walk test.

Conclusion

Patients with PAC tend to have a shortened survival. None of the evaluated parameters (BNP, TAPSE, sPAP) was correlated with the development of arrhythmias. Patients with multiform/repetitive PVC seem to be at risk for ventricular arrhythmias.

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.

The ratio of main pulmonary artery to ascending aorta diameter is associated with the right ventricular outflow tract ventriculararrhythmias

BACKGROUND

Although outflow tract (OT) ventricular arrhythmias (VAs) are generally regarded as benign, the relationship between circulation pressure and VAs has received considerable attention in recent years. Previous studies have shown that the ratio of main pulmonary artery (MPA) to ascending aorta (AA) diameter is associated with pulmonary pressure. Here, we investigated whether an elevated MPA/AA ratio is associated with right ventricular OT (RVOT) VAs.

METHODS

A total of 67 patients with OT VAs (47 patients with RVOT and 20 patients with LVOT) who underwent cardiac multidetector computed tomography and radiofrequency ablation were enrolled in this study. MPA and AA diameters were measured at the level of the bifurcation of the pulmonary artery. According to the MPA/AA ratio, patients were further divided into two groups: the MPA/AA ratio abnormal group (n = 19), which is defined as MPA/AA ratio ≥ 0.9, and the MPA/AA ratio normal group (n = 48) consisting of patients with an MPA/AA ratio < 0.9.

RESULTS

Patients with RVOT VAs exhibited an elevated MPA/AA ratio (0.84 ± 0.11 vs. 0.75 ± 0.11, p = 0.006). Furthermore, this MPA/AA ratio was shown to be an independent predictor for RVOT VAs (p = 0.013, 95% confidence interval: 1.016-1.145), with an abnormal MPA/AA ratio increasing the odds of RVOT VAs 5.1-fold in patients with OT VAs.

CONCLUSION

Patients with RVOT VAs exhibited significantly higher MPA/AA ratios compared with those LVOT VAs. The MPA/AA ratio was showed to be an independent predictor RVOT VAs.

[Tachycardia and pulmonary arterial hypertension]

Pulmonary hypertension is newly defined as an elevation of the mean pulmonary arterial pressure >20 mmHg and a pulmonary vascular resistance ≥3 Wood units. Arrhythmias are an increasing problem in patients with pulmonary hypertension. Pathophysiological aspects leading to supraventricular arrhythmias are atrial fibrosis caused by increased right atrial pressure and dilation. An increased sympathetic tone leads to prolongation of action potential and delayed polarisations causing arrhythmias. Therapy of arrhythmias includes drugs (preferred amiodarone) and electrophysiological therapy like electric cardioversion and ablation, which is safe in patients with pulmonary hypertension.

[Arrhythmias in patients with pulmonary hypertension and chronic lung disease]

Pulmonary arterial hypertension (PAH) occurs in 1% of the global population and can be divided in different disease groups. Pathophysiological aspects leading to supraventricular arrhythmias in these patients are due to increased pulmonary and right atrial pressure, increased activity of the sympathetic nervous system leading to right atrial electrical remodeling and ischemia in the right atrium. In the clinical setting these patients present with atrial flutter, atrial fibrillation or with ectopic atrial tachycardia. Regarding ventricular tachycardia there is a lack of data. Occurrence of arrhythmia in these patients leads to a deterioration of PAH, so rhythm control should be the aim. This can be achieved by right atrial ablation, especially in patients presenting with atrial flutter; electric cardioversion or antiarrhythmic drug therapy are without definite guideline recommendations since there are too few clinical trials. Ablation with a transseptal approach in the left atrium is considered rather dangerous and should be avoided. Regarding arrhythmias in patients with chronic lung disease, few data are available. For patients with chronic obstructive pulmonary disease (COPD), there are good data available. These patients often suffer from coronary heart disease, atrial fibrillation, and ventricular tachycardia. Beta-blockers play an important role in COPD patients, even during exacerbation. Interventional therapies are safe but the arrhythmogenic foci often located outside of the pulmonary veins (in the right atrium).

Arrhythmic Burden and Outcomes in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a devastating, life-limiting disease driven by small vessel vascular remodeling leading to a rise in pulmonary vascular resistance (PVR). Patients present with a range of symptoms including shortness of breath, exercise intolerance, palpitations or syncope. Symptoms may be related to vascular disease progression or arrhythmia secondary to the adaptation of the right heart to pressure overload. Arrhythmic burden is high in patients with left heart disease and guideline-based treatment of arrhythmias improves quality of life and prognosis. In PAH the incidence and prevalence of arrhythmias is less well-defined and there are no PAH-specific guidelines for arrhythmia management. We undertook a literature search identifying 13 relevant papers; detection of arrhythmias was acquired from 12-lead electrocardiogram (ECG) or Holter monitors. In all forms of pulmonary hypertension (PH) the prevalence of supraventricular arrhythmias (SVA) was 26-31%, ventricular arrhythmias (VA) 24% and a 5-year incidence of SVA ~13.2-25.1%. Prevalence and incidence of arrhythmias in PAH is less clear due to limited study numbers and the heterogenous nature of the patient population studied. For arrhythmia treatment, only single-arm studies of therapeutic strategies were reported using antiarrhythmic drugs (AAD), direct current cardioversion (DCCV) and ablation. Periods between ECG or Holter have not been investigated, highlighting the possibility that significant arrhythmias may be undetected. Advances in monitoring allow long-term surveillance via implanted/non-invasive monitors. Use of such technologies may provide an accurate estimate of incidence and prevalence of arrhythmias in patients with PAH, further defining relationships to adverse outcomes, and therapeutic options.

Pathophysiology, incidence, management, and consequences of cardiac arrhythmia in pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension

Arrhythmias are increasingly recognized as serious, end-stage complications of pre-capillary pulmonary hypertension, including pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH). Although arrhythmias contribute to symptoms, morbidity, in-hospital mortality, and possibly sudden death in PAH/CTEPH, there remains a paucity of epidemiologic, pathophysiologic, and outcome data to guide management of these patients. This review summarizes the most current evidence on the topic: from the molecular mechanisms driving arrhythmia in the hypertrophied or failing right heart, to the clinical aspects of epidemiology, diagnosis, and management.

Intra-tracheal gene delivery of aerosolized SERCA2a to the lung suppresses ventricular arrhythmias in a model of pulmonary arterial hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH) results in right ventricular (RV) failure, electro-mechanical dysfunction and heightened risk of sudden cardiac death (SCD), although exact mechanisms and predisposing factors remain unclear. Because impaired chronotropic response to exercise is a strong predictor of early mortality in patients with PAH, we hypothesized that progressive elevation in heart rate can unmask ventricular tachyarrhythmias (VT) in a rodent model of monocrotaline (MCT)-induced PAH. We further hypothesized that intra-tracheal gene delivery of aerosolized AAV1.SERCA2a (AAV1.S2a), an approach which improves pulmonary vascular remodeling in PAH, can suppress VT in this model.

OBJECTIVE

To determine the efficacy of pulmonary AAV1.S2a in reversing electrophysiological (EP) remodeling and suppressing VT in PAH.

METHODS

Male rats received subcutaneous injection of MCT (60 mg/kg) leading to advanced PAH. Three weeks following MCT, rats underwent intra-tracheal delivery of aerosolized AAV1.S2a (MCT + S2a, N = 8) or saline (MCT, N = 9). Age-matched rats served as controls (CTRL, N = 7). The EP substrate and risk of VT were determined using high-resolution optical action potential (AP) mapping ex vivo. The expression levels of key ion channel subunits, fibrosis markers and hypertrophy indices were measured by RT-PCR and histochemical analyses.

RESULTS

Over 80% of MCT but none of the CTRL hearts were prone to sustained VT by rapid pacing (P < .01). Aerosolized gene delivery of AAV1.S2a to the lung suppressed the incidence of VT to <15% (P < .05). Investigation of the EP substrate revealed marked prolongation of AP duration (APD), increased APD heterogeneity, a reversal in the trans-epicardial APD gradient, and marked conduction slowing in untreated MCT compared to CTRL hearts. These myocardial EP changes coincided with major remodeling in the expression of K and Ca channel subunits, decreased expression of Cx43 and increased expression of pro-fibrotic and pro-hypertrophic markers. Intra-tracheal gene delivery of aerosolized AAV1 carrying S2a but not luciferase resulted in selective upregulation of the human isoform of SERCA2a in the lung but not the heart. This pulmonary intervention, in turn, ameliorated MCT-induced APD prolongation, reversed spatial APD heterogeneity, normalized myocardial conduction, and suppressed the incidence of pacing-induced VT. Comparison of the minimal conduction velocity (CV) generated at the fastest pacing rate before onset of VT or at the end of the protocol revealed significantly lower values in untreated compared to AAV1.S2a treated PAH and CTRL hearts. Reversal of EP remodeling by pulmonary AAV1.S2a gene delivery was accompanied by restored expression of key ion channel transcripts. Restored expression of Cx43 and collagen but not the pore-forming Na channel subunit Nav1.5 likely ameliorated VT by improving CV at rapid rates in PAH.

CONCLUSION

Aerosolized AAV1.S2a gene delivery selectively to the lungs ameliorates myocardial EP remodeling and VT susceptibility at rapid heart rates. Our findings highlight for the first time the utility of a non-cardiac gene therapy approach for arrhythmia suppression.

Heart rate and risk of death among patients with Pulmonary Hypertension: A 12-lead ECG analysis

BACKGROUND

Despite the emergence of new therapies, Pulmonary Hypertension (PH) still has a high mortality. Several clinical, echocardiographic, biological or hemodynamic prognostic factors have been identified but are of limited predictive value for survival. We aimed to assess whether heart rate (HR) and all ECG abnormalities measured on a 12-lead ECG may help to better identify patients at high risk of death in this population.

METHODS AND RESULTS

296 patients followed in a registry were included with all types of PH, except group 2 of the WHO clinical classification. After a median follow-up of 10 years, age, male sex, NYHA III/IV status and, among all ECG parameters, HR and corrected QT interval were associated with mortality. In multivariate analysis, HR, age and male sex remained significant independent predictors of mortality. HR has a higher predictive value in the 238 patients in sinus rhythm. In addition, only HR was significantly correlated with clinical and hemodynamic PH prognostic factors.

CONCLUSION

HR measured on a 12-lead ECG at the time of the diagnosis is a strong independent predictor of mortality in PH patients.

Prognostic Relevance of Nonsustained Ventricular Tachycardia in Patients with Pulmonary Hypertension

Background. Increased pulmonary vascular resistance in patients with pulmonary hypertension (PH) leads to an increased afterload of right heart and cardiac remodeling which could provide the substrate or trigger for arrhythmias. Supraventricular arrhythmias were associated with clinical deterioration but were not associated with sudden cardiac death (SCD). SCD has been reported to account for approximately 30% of deaths in patients with pulmonary arterial hypertension (PAH). Objective. The role of nonsustained ventricular tachycardia (nsVT) and its prognostic relevance in patients with PH remains unclear. This study evaluated the prognostic relevance of nsVT in patients with PAH and chronic thromboembolic pulmonary hypertension (CTEPH). Methods. Retrospectively, patients with PAH and CTEPH who underwent Holter ECG monitoring and available data of survival were investigated. Results. Seventy-eight (PAH: 55, CTEPH: 23) patients were evaluated. Holter ECG revealed nsVT in 12 patients. Twenty-one patients died during follow-up. In patients with nsVT, tricuspid annular plane systolic excursion was lower (p = 0.001), and systolic pulmonary arterial pressure was higher (p = 0.163). Mean survival of patients without/with nsVT was 155.2 ± 8.5/146.4 ± 21.4 months (p = 0.690). The association between arrhythmias and survival was not confounded by age (p = 0.681), gender (p = 0.752), 6-MW distance (p = 0.196), or arterial hypertension (p = 0.238). Conclusions. In patients with PH, nsVT occurs more often than previously reported, and patients with PH group 1 seem to be more at risk.