Left atrial phasic function and heart rate variability in patients with systemic sclerosis: A new part of the old puzzle

Diagnosis and management of primary heart involvement in systemic sclerosis

PURPOSE OF REVIEW

In systemic sclerosis (SSc) primary heart involvement (pHI) is frequent, even though often unrecognized due to its occult nature and to the lack of a specific diagnostic algorithm. The purpose of this review is to report the state of the art of the evidence in the current literature, as well as the overall diagnostic modalities and therapeutic strategies for primary heart involvement in SSc.

RECENT FINDINGS

SSc-pHI is defined by the presence of cardiac abnormalities that are predominantly attributable to SSc rather than other causes and/or complications; it may be sub-clinical and must be confirmed through diagnostic investigations. Novel electrocardiographic analysis and cardiac magnetic resonance (CMR) with mapping techniques have been recently proposed, showing a great utility in the early identification of SSc-pHI and in the noninvasive characterization of myocardial tissue. Immunosuppressive therapy emerged as fundamental to curb myocardial inflammation, and recent preclinical and clinical data support the role of antifibrotic drugs to treat SSc-pHI.

SUMMARY

our review will help clinicians to properly integrate the available diagnostic modalities for the assessment of SSc-pHI. The ultimate goal is to propose a feasible diagnostic algorithm for the early identification of patients with SSc-pHI, and a schematic therapeutic approach to manage SSc-pHI.

Evaluation of cardiac autonomic control during the 6-min walk test in women with systemic sclerosis

OBJECTIVE

To evaluate the association between sympathovagal balance and exercise performance, as measured by the 6-min walk test (6MWT), in women with systemic sclerosis (SSc) without cardiac involvement.

RESULTS

This was a cross-sectional study in which 69 women with SSc [median age 51 (40-63 years)] without cardiac involvement underwent the 6MWT. Throughout the 6MWT, heart rate variability (HRV) was assessed using dedicated software.

METHODS

The median 6-min walking distance (6MWD) was 451 (392-498) meters, and 29 (42%) participants did not achieve 80% of the predicted value for healthy adults. Desaturation during the 6MWT (SpO2 ≤ 4%) was observed in 10.1% of participants. Significant correlations were observed between the 6MWD and the following HRV parameters: number of successive normal-to-normal RR interval differences > 50 ms (rs=-0.397, P = 0.013), low-frequency range (rs=0.374, P = 0.023), high-frequency range (rs=-0.372, P = 0.023), and parasympathetic nervous system index (rs=-0.342, P = 0.045).

CONCLUSION

In women with SSc, there is an interrelationship of the 6MWD with both vagal withdrawal and sympathetic hyperactivation. This relationship between autonomic imbalance and worse exercise performance might increase cardiovascular risk, even in patients without apparent cardiac involvement. Control of the heart by the autonomic nervous system may be a potential target for treating patients with SSc.

Cardiac involvement assessment in systemic sclerosis using speckle tracking echocardiography: a systematic review and meta-analysis

OBJECTIVES

Cardiac involvement in patients with systemic sclerosis (SSc) is associated with poor prognosis. Early detection of myocardial impairment is essential for treatment. The present study aimed to systematically review the value of detecting subclinical myocardial impairment in SSc patients using myocardial strain obtained from speckle tracking echocardiography (STE).

DESIGN

A systematic review and meta-analysis.

DATA SOURCES

The PubMed, Embase and Cochrane library databases were searched in the period from the earliest available indexing date to 30 September 2022.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies evaluating myocardial function in SSc patients comparison with healthy controls based on myocardial strain data obtained from STE were included.

DATA EXTRACTION AND SYNTHESIS

Ventricle and atrium data on myocardial strain were extracted to assessing the mean difference (MD).

RESULTS

A total of 31 studies were included in the analysis. Left ventricular global longitudinal strain (MD: -2.31, 95% CI -2.85 to -1.76), left ventricular global circumferential strain (MD: -2.93, 95% CI -4.02 to -1.84) and left ventricular global radial strain (MD: -3.80, 95% CI -5.83 to -1.77) was significantly lower in SSc patients than in healthy controls. Right ventricular global wall strain (MD: -2.75, 95% CI -3.25 to -2.25) was also decreased in SSc patients. STE revealed significant differences in several atrial parameters including left atrial reservoir strain (MD: -6.72, 95% CI -10.09 to -3.34) and left atrial conduit strain (MD: -3.26, 95% CI -6.50 to -0.03), as well as right atrial reservoir strain (MD: -7.37, 95% CI -11.20 to -3.53) and right atrial conduit strain (MD: -5.44, 95% CI -9.15 to -1.73). There were no differences in left atrial contractile strain (MD: -1.51, 95% CI -5.34 to 2.33).

CONCLUSION

SSc patients have a lower strain than healthy controls for the majority of STE parameters, indicating the presence of an impaired myocardium involving both the ventricle and atrium.

Clinical implication of disturbed left atrial phasic functions in the heterogeneous population associated with hypertension or atrial fibrillation

BACKGROUND

To evaluate left atrial (LA) phasic functions in patients with hypertension and/or paroxysmal atrial fibrillation (PAF) and its clinical significance.

METHODS

LA strain was studied in 77 patients (25 hypertension, 24 lone AF, and 28 with both hypertension and PAF) and 28 controls using two-dimensional speckle-tracking echocardiography (2D STE). The following indexes during atrial reservoir, conduit and pump phase were analyzed respectively: (1) peak atrial longitudinal strain (PALS) and strain rate (PALSR), (2) the standard deviation of time to PALS and PALSR of all LA segments (TpS-SD% and TpSR-SD%).

RESULTS

Compared with controls, PALS_res, PALS_cond and PALSR_cond were significantly reduced in patients with isolated hypertension (all P < 0.01) but no significant differences were observed in PALS_pump, PALSR_pump and TpS_pump-SD% between them (all P > 0.05). PALS_pump, PALSR_pump and PALSR_res were significantly lower in patients with both hypertension and PAF than in those with isolated hypertension (all P < 0.05). PALS and PALSR were significantly decreased, and TpS-SD% was significantly increased during each phase in lone AF patients than in controls (all P < 0.05), and PALSR_pump was further depressed in patients with both hypertension and PAF (P = 0.029). PALSR_cond ≤ 1.475 s^- 1 combined with TpS_pump-SD% ≥ 3.25% (sensitivity, 85%; specificity, 71%; AUC = 0.845, P < 0.001) could distinguish lone AF from healthy subjects effectively, while in hypertensive patients, PALS_pump ≤ 14.2% was found to be an independent differentiator for occurrence of AF or not with sensitivity of 81% and specificity of 84% (AUC = 0.838, P < 0.001). LAVI≥29.3 mL/m² was an independent characteristic for reflecting different LA remodeling in lone AF or hypertension with AF.

CONCLUSIONS

The impairment of LA phasic functions was varied in patients with hypertension and/or AF. The disturbed LA phasic functions were proved to have independent abilities of differential diagnosis in this heterogeneous population associated with hypertension or AF.

Cardiac autonomic modulation at rest and during orthostatic stress among different systemic sclerosis subsets

OBJECTIVE

To compare autonomic heart rate variability (HRV) parameters at rest and during active stand in a population of SSc patients, taking into account SSc subsets age-matched to healthy control subjects.

METHODS

Sixty-nine consecutive SSc patients were enrolled in study; these included 12 subjects with early SSc, 39 with limited cutaneous (lcSSc) and 18 with diffuse cutaneous SSc (dcSSc) along with 36 age- and sex-matched healthy controls (HC). ECG and respiration were recorded in supine position and in orthostatism (ORT). HRV analysis was performed on samples of 300 beats. Spectral analysis identified two oscillatory components, low frequency (LFnu, sympathetic) and high frequency (HFnu, vagal). Symbolic analysis identified three patterns, 0 V%, (sympathetic) and 2UV% and 2LV%, (vagal). The %∆ORT was calculated from the differences between HRV in ORT and SUP, normalized (%) by the HRV values at rest.

RESULTS

SSc as a whole had higher markers of sympathetic (LF, 0 V%) and lower markers of vagal modulation (HR, 2UV%, 2LV%) compared to HCs. In addition, %∆LFnu, %∆HFnu, %∆0 V, %∆2UV and %∆2LV were lower in SSc than HC. dcSSc and lcSSc were dissimilar to HC as far as rest indexes were concerned (↑LF/HF, ↑LFnu, ↓HFnu, ↑0 V% and ↓2UV%) while no differences could be detected between HC and EaSSc.

CONCLUSION

SSc showed a reduced vagal and increased sympathetic modulation at rest and a blunted autonomic response to ORT in comparison to HC. These alterations were mostly detectable in the advanced and fibrotic forms of SSc (dcSSc and lcSSc), while EaSSc were similar to HC.