Assessment of Cardiac Sympathetic Activity by Nuclear Medicine: Many Clinical Benefits but Weak Recommendation

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Russian Foundation for Basic Research Introduction Impaired cardiac sympathetic activity and contractility are associated with poor prognosis in patients with heart failure after cardiac resynchronization therapy (CRT). There are few prognostic data of the cardiac sympathetic activity and dyssynchrony in patients with chronic heart failure of various etiologies. Purpose To examine the prognostic significance of scintigraphic cardiac sympathetic activity and contractility in predicting the response to CRT and to assess the differences between patients with ischemic (IHF) and non-ischemic (NIHF) heart failure. Methods This study included 38 heart failure patients (24 male; mean age of 56 ± 11 years; 16 patients with ischemic etiology), who were submitted to CRT. Before CRT all patients underwent 123I-metaiodobenzylguanidine (123I-MIBG) imaging for cardiac sympathetic activity evaluating: early and delay heart to mediastinum ratio (eH/M and dH/M), summed MIBG Score (eSMS and dSMS). Moreover all patients underwent gated SPECT with the assessments of left ventricle dyssynchrony indexes: standard deviation (SD) and histogram bandwidth (HBW). In addition, all patients underwent gated blood-pool SPECT (GBPS) to assessed ejection fraction (EF) and stroke volume (SV) of both ventricles. Results One year after CRT response defined as LV ESV decreased by≥15% and/or LV EF increase by≥5%. Baseline cardiac sympathetic activity parameters showed significant differences between responders and non-responders only in NIHF patients: eH/M: 2.27 (2.02–2.41) vs. 1.64 (1.32–2.16); dH/M: 2.18 (2.11–2.19) vs. 1.45 (1.23 – 1.61); eSMS: 7 (5-7) vs. 15.5 (10–28.5); dSMS: 10 (10–13) vs. 16.5 (15.5–29). Significant differences in baseline LV dyssynchrony indexes between responders and non-responders were in patients of both group: in NIHF patients - SD: 54.3 (43–58) degree vs. 65 (62–66) degree; HBW: 179.5 (140–198) degree vs. 211 (208-213) degree, p < 0.054 in IHF patients - HBW: 162 (115.2–180) degree vs. 115.2 (79.2–136.8) degree. Contractility of RV was significantly differed between responders and non-responders in IHF patients: RV EF: 54.5 (41-56) % vs. 44.5 (37–49.5) %; RV SV: 80 (69-101) ml vs. 55.5 (50–72.5) ml. According to univariate logistic regression analyses in IHF patients LV dyssynchrony indexes – SD (OR = 1.55; 95% CI 1.09-2.2; p < 0.5) and HBW (OR = 1.13; 95% CI 1.02-1.24; p < 0.5), as well as RV indexes – RV EF (OR = 1.11; 95% CI 1.001-1.23; p < 0.5), RV SV (OR = 1.07; 95% CI 1.003-1.138; p < 0.5) were predictors of CRT response. In the group of NIHF patients, dH/M (OR = 1.47; 95% CI 1.08-2; p < 0.5), SD (OR = 0.83; 95% CI 0.73-0.95; p < 0.5), HBW (OR = 0.96; 95% CI 0.93-0.99; p < 0.5) showed the predictive value in terms of CRT response. Conclusion Scintigraphic methods can be used to select patients for CRT. Cardiac 123I-MIBG scintigraphy and gated SPECT may be used for predicting CRT response in NIHF patients. Whereas in IHF patients ECG-gated SPECT and GBPS may be valuable for predicting the response to CRT.

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Cardiac Sympathetic Activity by 123I-Meta-Iodobenzylguanidine Imaging in Women With Coronary Microvascular Dysfunction

JACC Cardiovascular Imaging ◽

10.1016/j.jcmg.2021.03.031 ◽

2021 ◽

Author(s):

Puja K. Mehta ◽

Louise E.J. Thomson ◽

Piotr J. Slomka ◽

Sean W. Hayes ◽

John D. Friedman ◽

...

Keyword(s):

Sympathetic Activity ◽

Microvascular Dysfunction ◽

Coronary Microvascular Dysfunction ◽

Cardiac Sympathetic Activity

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GW27-e1105 Endothelin-1 in Left Stellate Ganglion Promotes Post-infarction Ventricular Arrhythmias by Increasing Cardiac Sympathetic Activity

Journal of the American College of Cardiology ◽

10.1016/j.jacc.2016.07.239 ◽

2016 ◽

Vol 68 (16) ◽

pp. C65

Author(s):

Zhou Liping ◽

Lilei Yu ◽

Hong Jiang

Keyword(s):

Sympathetic Activity ◽

Ventricular Arrhythmias ◽

Stellate Ganglion ◽

Cardiac Sympathetic Activity ◽

Endothelin 1 ◽

Left Stellate Ganglion

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Plasma catecholamines, heart rate, and cardiac sympathetic activity in exercising dogs

Medicine & Science in Sports & Exercise ◽

10.1249/00005768-198204000-00005 ◽

1982 ◽

Vol 14 (4) ◽

pp. 281-285 ◽

Cited By ~ 2

Author(s):

FRANÇOIS PÉRONNET ◽

RÉGINALD NADEAU ◽

JACQUES de CHAMPLAIN ◽

CLAUDE CHARTRAND

Keyword(s):

Heart Rate ◽

Sympathetic Activity ◽

Plasma Catecholamines ◽

Cardiac Sympathetic Activity

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Immediate changes in cardiac autonomic tone and stroke volume during microgravity simulation using head-down tilt

Indian Journal of Physiology and Pharmacology ◽

10.25259/ijpp_2_2021 ◽

2021 ◽

Vol 65 ◽

pp. 86-93

Author(s):

Vishwajeet Shankhwar ◽

Dilbag Singh ◽

K. K. Deepak

Keyword(s):

Stroke Volume ◽

Blood Volume ◽

Sympathetic Activity ◽

Cardiovascular Responses ◽

Significant Rise ◽

Vagal Activity ◽

Autonomic Tone ◽

Cardiac Sympathetic Activity ◽

Microgravity Simulation ◽

Frequency Power

Objectives: Gravity plays an important role in the day-to-day functioning of the cardiovascular system (CVS) in the human body. The absence of gravity severely affects CVS functioning. Out of existing simulation models of microgravity, the 6° head-down tilt (HDT) is frequently used analog to replicate the physiological effects of microgravity on earth. Materials and Methods: The present study has been designed to determine the specificity of 6° HDT usage as a microgravity simulation. The heart rate variability (HRV), blood pressure (BP), cardiac output (CO), and stroke volume (SV) responses to 5 min exposures were investigated for 4°, 6°, and 8° HDT. It was hypothesized that the graded HDT around 6° will demonstrate reversal of autonomic parameters. The study was conducted on 28 male subjects aged 20–30 years. Results: The study reveals that there was a significant rise in diastolic and mean BP at 6° and 8° HDT as compared to baseline. It was also observed that the high-frequency power in HRV was increased at 6° HDT (P = 0.026), with a concomitant reduction in the low-frequency power (P = 0.03) of HRV. The CO was increased at 6° and 8° HDT as compared to baseline (P = 0.037 and 0.021, respectively). There were no significant changes observed in any of the recorded parameters at 4° HDT. The cardiopulmonary volume receptors might have sensed the blood volume change in HDT as in microgravity simulation the blood passively shifts to cephalad. To overcome the low blood volume problem, the heart tried to pump extra blood through increased CO. At 8° HDT, it was observed that the cardiac sympathetic activity and CO were increased, which is not observed during microgravity exposures. Conclusion: The study suggests that 6° head-down-tilt is the best tilt level for producing microgravity on earth to study immediate cardiovascular parameters as it is a balanced compromise of increased vagal activity and CO without activation of cardiac sympathetic activity. Therefore, our data provide physiological evidence in support of 6° HDT microgravity simulation for the study of immediate cardiovascular responses.

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