Right atrium enlargement predicts clinically significant supraventricular arrhythmia in patients with pulmonary arterial hypertension

Mechanisms of pulmonary arterial hypertension-induced atrial fibrillation: insights from multi-scale models of the human atria

This study aimed to use multi-scale atrial models to investigate pulmonary arterial hypertension (PAH)-induced atrial fibrillation mechanisms. The results of our computer simulations revealed that, at the single-cell level, PAH-induced remodelling led to a prolonged action potential (AP) (ΔAPD: 49.6 ms in the right atria (RA) versus 41.6 ms in the left atria (LA)) and an increased calcium transient (CaT) (ΔCaT: 7.5 × 10-2 µM in the RA versus 0.9 × 10-3 µM in the LA). Moreover, heterogeneous remodelling increased susceptibility to afterdepolarizations, particularly in the RA. At the tissue level, we observed a significant reduction in conduction velocity (CV) (ΔCV: -0.5 m s-1 in the RA versus -0.05 m s-1 in the LA), leading to a shortened wavelength in the RA, but not in the LA. Additionally, afterdepolarizations in the RA contributed to enhanced repolarization dispersion and facilitated unidirectional conduction block. Furthermore, the increased fibrosis in the RA amplified the likelihood of excitation wave breakdown and the occurrence of sustained re-entries. Our results indicated that the RA is characterized by increased susceptibility to afterdepolarizations, slow conduction, reduced wavelength and upregulated fibrosis. These findings shed light on the underlying factors that may promote atrial fibrillation in patients with PAH.

Evidence of Failed Resolution Mechanisms in Arrhythmogenic Inflammation, Fibrosis and Right Heart Disease

Inflammation is a complex program of active processes characterized by the well-orchestrated succession of an initiation and a resolution phase aiming to promote homeostasis. When the resolution of inflammation fails, the tissue undergoes an unresolved inflammatory status which, if it remains uncontrolled, can lead to chronic inflammatory disorders due to aggravation of structural damages, development of a fibrous area, and loss of function. Various human conditions show a typical unresolved inflammatory profile. Inflammatory diseases include cancer, neurodegenerative disease, asthma, right heart disease, atherosclerosis, myocardial infarction, or atrial fibrillation. New evidence has started to emerge on the role, including pro-resolution involvement of chemical mediators in the acute phase of inflammation. Although flourishing knowledge is available about the role of specialized pro-resolving mediators in neurodegenerative diseases, atherosclerosis, obesity, or hepatic fibrosis, little is known about their efficacy to combat inflammation-associated arrhythmogenic cardiac disorders. It has been shown that resolvins, including RvD1, RvE1, or Mar1, are bioactive mediators of resolution. Resolvins can stop neutrophil activation and infiltration, stimulate monocytes polarization into anti-inflammatory-M2-macrophages, and activate macrophage phagocytosis of inflammation-debris and neutrophils to promote efferocytosis and clearance. This review aims to discuss the paradigm of failed-resolution mechanisms (FRM) potentially promoting arrhythmogenicity in right heart disease-induced inflammatory status.

Systemic Sclerosis Portends Increased Risk of Conduction and Rhythm Abnormalities at Diagnosis and During Disease Course: A US Population-Based Cohort

Objectives

To study the incidence, risk factors and outcomes of conduction and rhythm disorders in a population-based cohort of patients with systemic sclerosis (SSc) vs. non-SSc comparators.

Methods

An incident cohort of patients with SSc (1980-2016) from Olmsted County, MN was compared to age- and sex-matched non-SSc subjects (1:2). Electrocardiograms (ECGs), Holter ECGs, and need for cardiac interventions were reviewed to determine the occurrence of any conduction or rhythm abnormalities.

Results

78 incident SSc cases and 156 comparators were identified (mean age 56 y, 91% female). The prevalence of any conduction disorder prior to SSc diagnosis compared to non-SSc subjects was 15% vs. 7% (p=0.06), and any rhythm disorder was 18% vs. 13% (p=0.33). During a median follow-up of 10.5 years in patients with SSc and 13.0 years in non-SSc comparators, conduction disorders developed in 25 patients with SSc with cumulative incidence of 20.5% (95% CI: 12.4-34.1%) vs. 28 non-SSc patients with cumulative incidence of 10.4% (95% CI: 6.2-17.4%) (HR: 2.57; 95% CI: 1.48-4.45), while rhythm disorders developed in 27 patients with SSc with cumulative incidence of 27.3% (95% CI: 17.9-41.6%) vs. 43 non-SSc patients with cumulative incidence of 18.0% (95% CI: 12.3-26.4%) (HR: 1.62; 95% CI: 1.00-2.64). Age, pulmonary hypertension and smoking were identified as risk factors.

Conclusion

Patients with SSc have an increased risk of conduction and rhythm disorders both at disease onset and over time, compared to non-SSc patients. These findings warrant increased vigilance and screening for ECG abnormalities in SSc patients with pulmonary hypertension.

The spectrum and prevalence of arrhythmia in different clinical pulmonary hypertension groups in Chinese population

BACKGROUND

Arrhythmia is not uncommon among pulmonary hypertension (PH) population, and may be associated with disease severity.

HYPOTHESIS

To investigate different spectrums and prevalence of arrhythmias in different clinical PH groups in Chinese population.

METHODS

Patients diagnosed with PH between April 15, 2019, and August 2, 2021, were enrolled prospectively. The prevalence of different types of arrhythmias in PH patients were calculated. Logistic regression analyses were conducted to determine independent predictors for arrhythmia.

RESULTS

One thousand patients were enrolled. The prevalence of any arrhythmia, sinus node dysfunction, sinus tachycardia, atrial fibrillation, atrial flutter, other types of atrial tachycardia, atrioventricular block, and ventricular tachycardia is 44.4%, 12.2%, 15.2%, 8.1%, 4.1%, 10.2%, 7.1%, and 2.5%. Logistic regression analyses revealed that older age and larger right ventricle (odds ratio: 1.111 and 1.095, p < .05) were independently related with higher probability of supraventricular arrhythmia; Complicating with coronary artery disease, larger right ventricle, and increased left ventricular end-diastolic diameter (odds ratio: 19.540, 1.106, and 1.085, p < .05) were independently correlated with sinus node dysfunction/atrioventricular block in patients with pulmonary arterial hypertension.

CONCLUSIONS

Nearly half of PH patients experienced at least one type of arrhythmia. The most common seen arrhythmias were supraventricular arrhythmia, sinus tachycardia, and sinus node dysfunction. Older age and larger right ventricle were independently related with higher probability of supraventricular arrhythmia; Complicating with coronary artery disease, larger right ventricle and increased left ventricular end-diastolic diameter were independently correlated with higher probability of sinus node dysfunction/atrioventricular block in patients with pulmonary arterial hypertension.

Association Between the Coronary Sinus Ostial Size and Atrioventricular Nodal Reentrant Tachycardia in Patients With Pulmonary Arterial Hypertension

Aims

The incidence of atrioventricular nodal reentrant tachycardia (AVNRT) is higher in pulmonary arterial hypertension (PAH) patients than in the general population. AVNRT is reportedly associated with a larger coronary sinus (CS) ostium (CSo). However, the correlation between AVNRT and CSo size in PAH patients is poorly investigated. We aimed to investigate the impact of CSo size on AVNRT and identify its risk factors in PAH.

Methods and Results

Of 102 PAH patients with catheter ablation of supraventricular tachycardia (SVT), twelve with a confirmed AVNRT diagnosis who underwent computed tomographic angiography were retrospectively enrolled as the study group. The control group (PAH without SVT, n = 24) was matched for sex and BMI at a 2:1 ratio. All baseline and imaging data were collected. Mean pulmonary artery pressure was not significantly different between the two groups (65.3 ± 16.8 vs. 64.5 ± 17.6 mmHg, P = 0.328). PAH patients with AVNRT were older (45.9 ± 14.8 vs. 32.1 ± 7.6 years, P = 0.025), had a larger right atrial volume (224.4 ± 129.6 vs. 165.3 ± 71.7 cm3, P = 0.044), larger CSo in the left anterior oblique (LAO) plane (18.6 ± 3.3 vs. 14.8 ± 4.0 mm, P = 0.011), and larger CSo surface area (2.08 ± 1.35 vs. 1.45 ± 0.73 cm2, P = 0.039) and were more likely to have a windsock-shape CS (75% vs. 16.7%, P = 0.001) than those without AVNRT. A linear correlation was shown between CSo diameter in the LAO-plane and the atrial fractionation of the ablation target for AVNRT (R2 = 0.622, P = 0.012).

Conclusion

Anatomical dilation of the CSo is a risk factor for AVNRT development in patients with PAH.

Risk Factors of Pulmonary Arterial Hypertension and Its Relationship With Atrial Fibrillation in Patients With Obstructive Hypertrophic Cardiomyopathy

Background: Pulmonary arterial hypertension (PH) is a common complication in patients with obstructive hypertrophic cardiomyopathy (OHCM). The risk factor of PH in patients with OHCM has not been fully elucidated, and even atrial fibrillation (AF) was considered a risk factor of PH. Thus, our study aimed to investigate risk factors of PH and the relationship between PH and AF in patients with OHCM.

Methods: We retrospectively enrolled 483 consecutive patients diagnosed with OHCM at Fuwai Hospital (Beijing, China) from January 2015 to December 2017. Clinical and echocardiographic parameters were compared between patients with and without PH.

Results: Eighty-two (17.0%) patients were diagnosed with PH in this study. Compared to patients without PH, those with PH were significantly older, had a lower body mass index (BMI), were more likely to be female and more symptomatic [New York Heart Association Class 3 or 4 symptoms], and had a higher AF prevalence. A multivariate analysis indicated that AF was an independent risk factor of PH (odds ratio [OR] 2.31, 95% confidence interval [CI] 1.03–5.20, p = 0.042). Moreover, PH was independently associated with a higher AF incidence after adjusting for age and left atrial diameter (OR 2.24, 95% CI 1.07–4.72, p = 0.034).

Conclusion: AF was independently associated with PH in patients with OHCM. Further, PH was significantly associated with an increased risk of AF, which suggested that AF could aggravate PH and that PH may promote AF processes, forming a vicious circle.

[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.

Impact of Preoperative Measurement of Right Heart Chambers in the Evaluation of Pulmonary Hypertension Following Aortic Valve Replacement

BACKGROUND

Severe pulmonary hypertension (PH) in patients with aortic stenosis is related to poor prognosis following aortic valve replacement (AVR). Current European PH guidelines recommend adding two different echocardiographic signs to tricuspid regurgitation velocity (TRV) in PH estimation, classifying its probability as low (TRV ≤ 2.8 m/s), intermediate (TRV 2.9-3.4 m/s), and high (TRV > 3.4 m/s). The right ventricle is an important determinant of prognosis in PH. The goal of this study was to analyze the value of right atrial area > 18 cm² and right ventricular/left ventricular ratio > 1 in the long-term prognosis following AVR, mainly in the intermediate probability group.

METHODS

This study included 429 consecutive patients (mean age, 73 ± 8 years; 55% male) with a median follow-up of 4.25 years (completed in 98%). Patients were divided into low (n = 247), intermediate (n = 117), and high probability groups (n = 65). The intermediate probability group was divided into two subgroups: subgroup 2a (n = 27; TRV nonmeasurable or ≤ 2.8 m/s and two signs present) and subgroup 2b (n = 90; TRV 2.9-3.4 m/s, and none or only one sign present).

RESULTS

Overall mortality rates during follow-up of the low, intermediate, and high probability groups were 24%, 32%, and 42%, respectively. High PH probability was an independent predictor of all-cause mortality (hazard ratio [HR], 1.82; 95% CI, 1.11-3.00), but the intermediate probability group did not reach significance following multivariate analysis (HR, 1.40; 95% CI, 0.91-2.16). When the intermediate probability group was divided into subgroups, the subgroup 2a mortality rate (56%) was higher than that of both subgroup 2b (24%; P = .002) and the low probability group (24%; P < .001). Following multivariate analysis, subgroup 2a showed a significantly higher mortality (HR, 2.13; 95% CI, 1.11-4.10) in contrast to subgroup 2b (HR, 1.24; 95% CI, 0.75-2.05), both compared with the low probability group.

CONCLUSIONS

Incorporating measurement of the right cavities into the PH probability model in the assessment of long-term prognosis following AVR allowed better risk discrimination, especially in the intermediate probability group.

Correlations of Circadian Rhythm Disorder of Blood Pressure with Arrhythmia and Target Organ Damage in Hypertensive Patients

Background

The aim of this study was to investigate the correlations of circadian rhythm disorder of blood pressure with arrhythmia and target organ damage in hypertensive patients.

Material/Methods

A total of 198 patients admitted and treated in our hospital from May 2018 to April 2019 were selected to receive 24-h ambulatory blood pressure monitoring. The nighttime blood pressure decrease rate is 0–10% in people with normal circadian rhythm of blood pressure. In the present study, we divided patients into a normal circadian rhythm group (normal circadian rhythm of blood pressure, n=132) and a circadian rhythm disorder group (circadian rhythm disorder of blood pressure, n=66) according to the circadian rhythm of blood pressure. The systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean pulse pressure (PP) were observed, and dynamic electrocardiography was performed to observe the status of arrhythmia. Finally, the degree of damage to target organs such as heart, brain, and kidney was compared.

Results

The circadian rhythm disorder group had remarkably higher daytime SBP (d-SBP), daytime DBP (d-DBP), and daytime PP (d-PP) but clearly lower nighttime SBP (n-SBP), nighttime DBP (n-DBP), and nighttime PP (n-PP) than in the normal circadian rhythm group (P<0.0001). The detection rate of arrhythmia and the degree of target organ damage were clearly higher in the circadian rhythm disorder group compared with the normal circadian rhythm group (P<0.0001). Moreover, the incidence rates of heart disease, cerebrovascular disease, and nephropathy were higher in the circadian rhythm disorder group than in the normal circadian rhythm group (P<0.0001).

Conclusions

The circadian rhythm disorder of blood pressure in hypertensive patients probably increases the risk of arrhythmia and worsens the target organ damage, so attention should be paid to the adjustment of disordered blood pressure rhythm in hypertensive patients in clinical practice.

[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).

The left atrial substrate plays a significant role in the development of complex atrial tachycardia in patients with precapillary pulmonary hypertension

Background

Atrial fibrillation (AF) and related atrial tachyarrhythmias (AT), including type I atrial flutter (AFL) are frequently observed in patients with pulmonary hypertension (PH). Their relationship to hemodynamic changes, atrial size, and ventricular function are still not fully verified.

Methods

We retrospectively studied hemodynamic data, echocardiographic findings and arrhythmia incidence in 814 patients with invasively diagnosed precapillary PH (aged 59 ± 14 years; 46% males). Patients with combined or post-capillary PH were excluded.

Results

AF / AT were identified in 225 (28%) of all the study population. Compared to the subgroup without arrhythmia, patients with AF / AT had elevated right atrial pressure (11 ± 5 vs. 9 ± 5 mmHg), wedge pressure (11 ± 3 vs. 10 ± 3), a more enlarged right atrium (50 ± 12 vs. 47 ± 11 mm) and an increased left atrial diameter in the parasternal long axis projection, p <  0.05 for all comparisons. In the multivariate model, the left atrial size, patient age, arterial hypertension, diabetes and type of PH were associated with AF / AT occurrence, p <  0.05. Patients with type I AFL were more frequently male (39 (80%) vs. 62 (42%)), were younger (61 ± 11 vs. 67 ± 10 years), had increased pulmonary artery mean pressure (50 ± 12 vs. 45 ± 12 mmHg), less advanced left atrial dilatation (38 ± 10 vs. 42 ± 7 mm), and a more enlarged right atrium (56 ± 12 vs. 48 ± 11) as compared to subjects with AF or other AT, p <  0.05.

Conclusions

The evidence of elevated wedge pressure and the enlargement of the left atrium especially in patients with AF suggest a parallel involvement of the left atrial substrate in arrhythmia formation despite invasively confirmed evidence of purely isolated precapillary PH. Substantial differences were noticed between patients with type I AFL and the remaining patients with other arrhythmia types.

Left and Right Atrial Function and Remodeling in Beta-Thalassaemia Major

This study aimed to assess left (LA) and right atrial (RA) function in patients with beta-thalassaemia major. Thirty-eight patients (19 males) aged 34.5 ± 10.7 years and 43 (18 males) controls aged 30.3 ± 12.6 years (p = 0.12) were studied. The maximum RA and LA areas were measured using two-dimensional planimetry, while atrial and ventricular strain and strain rates were quantified using speckle-tracking echocardiography. Compared with controls, patients had significantly reduced LA and RA peak positive strain and total strain, and LA strain rate during ventricular systole and at atrial contraction (all p < 0.05). The LA and RA strain parameters were significantly associated (all p < 0.05). The maximum LA (10.2 ± 1.6 cm²/m² vs. 8.6 ± 1.3 cm²/m², p < 0.001) and RA (9.2 ± 1.2 cm²/m² vs. 7.5 ± 1.3 cm²/m², p < 0.001) areas were significantly greater in patients than controls. The LV and RV strain and early strain rates were similar between patients and controls (all p > 0.05). Four patients with significant myocardial iron overload had larger LA area (p < 0.001) than those without. Functional and structural remodeling of both the right and left atria occurs in patients with beta-thalassaemia major, even in the absence of ventricular diastolic dysfunction.

Going beyond Cardiomegaly: Evaluation of Cardiac Chamber Enlargement at Non-Electrocardiographically Gated Multidetector CT: Current Techniques, Limitations, and Clinical Implications

Cardiac chamber enlargement is important in the prediction of morbidity and mortality for a multitude of cardiovascular processes. Although non-electrocardiographically (ECG) gated multidetector CT is a commonly used cross-sectional imaging modality to evaluate a litany of cardiothoracic processes, a standardized method for evaluating and reporting cardiac chamber size does not exist. This has led to heterogeneity in the reporting of cardiac enlargement at routine multidetector CT with most readers often using gestalt assessment and the term cardiomegaly, which does not implicate the chamber or chambers that are enlarged. The purpose of this review article is to highlight advantages and limitations of several techniques used to assess cardiac chamber size at non-ECG-gated multidetector CT and to provide readers with reproducible and rapid measurements to determine if cardiac chamber size is present. The long-term aim would be to promote discussions between radiologists and institutions that would result in improved accuracy and decreased variability when commenting on cardiac chamber size. © RSNA, 2019.

Atrial contractility and fibrotic biomarkers are associated with atrial fibrillation after elective coronary artery bypass grafting

OBJECTIVE

New-onset postoperative atrial fibrillation is common after cardiac surgery. Less has been reported about the relationship among fibrosis, inflammation, calcium-induced left atrial and right atrial contractile forces, and postoperative atrial fibrillation. We sought to identify predictors of postoperative atrial fibrillation.

METHODS

From August 2016 to February 2018, we evaluated 229 patients who had preoperative sinus rhythm before elective primary coronary artery bypass grafting. Of 229 patients, 191 maintained sinus rhythm postoperatively, whereas 38 patients developed atrial fibrillation. Preoperative tissue inhibitor of metalloproteinase-1, pentraxin-3, matrix metallopeptidase-9, galectin-3, high-sensitivity C-reactive protein, growth differentiation factor 15, and transforming growth factor-ß were measured. Clinical and echocardiographic findings (tricuspid annular plane systolic excursion for right heart function) and calcium-induced force measurements from left atrial and right atrial-derived skinned myocardial fibers were recorded.

RESULTS

Patients with atrial fibrillation were older (P = .001), had enlarged left atrial (P = .0001) and right atrial areas (P = .0001), and had decreased tricuspid annular plane systolic excursion (P = .001). Levels of matrix metallopeptidase-9 and pentraxin-3 were decreased (P < .05), whereas growth differentiation factor 15 was increased (P = .001). We detected lower left atrial force values at calcium-induced force measurements 5.5 (P < .05), 5.4 (P < .01), and 5.3 to 4.52 (P = .0001) and right atrial force values at calcium-induced force measurements 5.0 to 4.52 (P < .05) in patients with postoperative atrial fibrillation. Multivariable analysis showed that advanced age (P = .033), decreased left atrial force value at calcium-induced force measurement of 5.5 (P = .033), enlarged left atrial (P = .013) and right atrial (P = .081) areas, and reduced tricuspid annular plane systolic excursion (P = .010) independently predicted postoperative atrial fibrillation.

CONCLUSIONS

Advanced age, decreased left atrial force value at calcium-induced force measurement of 5.5, enlarged left atrial and right atrial areas, and reduced tricuspid annular plane systolic excursion were identified as independent predictors for postoperative atrial fibrillation.

Atrial arrhythmias are associated with increased mortality in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a deadly vascular disease, characterized by increased pulmonary arterial pressures and right heart failure. Considering prior non-US studies of atrial arrhythmias in PAH, this retrospective, regional multi-center US study sought to define more completely the risk factors and impact of paroxysmal and non-paroxysmal forms of atrial fibrillation and flutter (AF/AFL) on mortality in this disease. We identified patients seen between 2010 and 2014 at UPMC (Pittsburgh) hospitals with hemodynamic and clinical criteria for PAH or chronic thromboembolic pulmonary hypertension (CTEPH) and determined those meeting electrocardiographic criteria for AF/AFL. We used Cox proportional hazards regression with time-varying covariates to analyze the association between AF/AFL occurrence and survival with adjustments for potential cofounders and hemodynamic severity. Of 297 patients with PAH/CTEPH, 79 (26.5%) suffered from AF/AFL at some point. AF/AFL was first identified after PAH diagnosis in 42 (53.2%), identified prior to PAH diagnosis in 27 (34.2%), and had unclear timing in the remainder. AF/AFL patients were older, more often male, had lower left ventricular ejection fractions, and greater left atrial volume indices and right atrial areas than patients without AF/AFL. AF/AFL (whether diagnosed before or after PAH) was associated with a 3.81-fold increase in the hazard of death (95% CI 2.64-5.52, p < 0.001). This finding was consistent with multivariable adjustment of hemodynamic, cardiac structural, and heart rate indices as well as in sensitivity analyses of patients with paroxysmal versus non-paroxysmal arrhythmias. In these PAH/CTEPH patients, presence of AF/AFL significantly increased mortality risk. Mortality remained elevated in the absence of a high burden of uncontrolled or persistent arrhythmias, thus suggesting additional etiologies beyond rapid heart rate as an explanation. Future studies are warranted to confirm this observation and interrogate whether other therapies beyond rate and rhythm control are necessary to mitigate this risk.