Coronary artery disease affects cortical circuitry associated with brain-heart integration during volitional exercise

Abstract

Norton KN, Badrov MB, Barron CC, Suskin N, Heinecke A, Shoemaker JK. Coronary artery disease affects cortical circuitry associated with brain-heart integration during volitional exercise. J Neurophysiol 114: 835-845, 2015. First published May 13, 2015 doi:10.1152/jn.00008.2015.-This study tested the hypothesis that coronary artery disease (CAD) alters the cortical circuitry associated with exercise. Observations of changes in heart rate (HR) and in cortical blood oxygenation level-dependent (BOLD) images were made in 23 control subjects [control; 8 women; 63 Ϯ 11 yr; mean arterial pressure (MAP): 90 Ϯ 9 mmHg] (mean Ϯ SD) and 17 similarly aged CAD patients (4 women; 59 Ϯ 9 yr; MAP: 87 Ϯ 10 mmHg). Four repeated bouts each of 30%, 40%, and 50% of maximal voluntary contraction (MVC) force (LAB session), and seven repeated bouts of isometric handgrip (IHG) at 40% MVC force (fMRI session), were performed, with each contraction lasting 20 s and separated by 40 s of rest. There was a main effect of group (P ϭ 0.03) on HR responses across all IHG intensities. Compared with control, CAD demonstrated less task-dependent deactivation in the posterior cingulate cortex and medial prefrontal cortex, and reduced activation in the right anterior insula, bilateral precentral cortex, and occipital lobe (P Ͻ 0.05). When correlated with HR, CAD demonstrated reduced activation in the bilateral insula and posterior cingulate cortex, and reduced deactivation in the dorsal anterior cingulate cortex, and bilateral precentral cortex (P Ͻ 0.05). The increased variability in expected autonomic regions and decrease in total cortical activation in response to the IHG task are associated with a diminished HR response to volitional effort in CAD. Therefore, relative to similarly aged and healthy individuals, CAD impairs the heart rate response and modifies the cortical patterns associated with cardiovascular control during IHG.

Forebrain Network Associated With Cardiovascular Control in Exercising Humans

“…Must the MPFC and HC act in synchrony to achieve a robust tachycardiac at the exercise onset? In limited studies, we have observed diminished HR responses to 35%–40% maximal strength handgrip contractions in older compared with younger individuals ( 1 ), a response that was diminished further in older adults with ischemic heart disease ( 6 ). In these older groups, the changes in MPFC and HC activity often were heterogenous such that a pattern of reduced activity was observed in only one of the two sites.…”

“…This response also represents clinical interests. Specifically, the response is blunted severely in aging individuals ( 1 ) and in those with heart disease ( 6 ). As the cardiovascular adjustments during this period exert critical influence on oxygen usage in the active muscle ( 7 ), and slow oxygen uptake kinetics are associated with poor exercise intolerance ( 8 ), understanding the regulation of cardiac function at the exercise onset has important implications not only for general knowledge of neural control of the circulation but also of how this concept affects, or relates to, health and disease.…”

The Cardiovascular Stress Response as Early Life Marker of Cardiovascular Health: Applications in Population-Based Pediatric Studies—A Narrative Review

“…Higher age was associated with reduced increase of stroke volume and cardiac output Overweight subjects showed less increases in heart rate and cardiac output Leucker (2018) [ 93 ] 48 HIV + patients: age: 49 ± 8 years 15 healthy subjects: age: 52 ± 12 years 4 to 7 min at 30% MVC Coronary MRI CEF was significantly reduced in the HIV + versus HIV- subjects Macey (2017) [ 94 ] 63 healthy subjects: age: 47.0 ± 9.1 years 4 × 16 s challenges at 80% MVC FMRI of the brain Females showed higher resting HR than males, but smaller percent HR change increases during exercise Mathews (2017) [ 95 ] 30 healthy women: age: 49.8 ± 16.7 years 20 healthy men: age: 44.1 ± 16.4 years 5–6 min at 30% MVC Coronary MRI In men baseline CSA was 13.4 ± 4.6 mm 2 and increased 8.8 ± 5.2% with IHE. In women baseline CSA was 10.7 ± 2.6mm 2 , and increased 1.4 ± 9.6% with IHE Men: HR increase: 20,0% Systolic BP increase: 10,7% Diastolic BP increase: 15,9%: RPP increase: 33,9% Women: HR increase: 17,2% Systolic BP increase: 8,0% Diastolic BP increase: 17,9% RPP increase: 28,1% Norton (2013) [ 96 ] 29 subjects: age: 21–80 years 40% MVC FMRI of the brain The average change in HR from baseline was 6BPM Norton (2015) [ 97 ] 23 healthy subjects: age: 63 years 17 patients with CAD: age: 59 years 7 repeated bouts at 40% MVC with each contraction lasting 20 s and separated by 40 s of rest FMRI of the brain HR during exercise in control participants was greater than CAD patients Specifically, young individuals (25 ± 4 year) have a larger HR response (6–15 beats/min) to a similar relative IHE tension Rokamp (2014) [ 98 ] 11 healthy subjects: age: 24 ± 3 years Squeeze 30–60 times per minute with as much effort as possible FMRI of the brain Diastolic BP increase: 4 mmHg Mean BP increase: 5 mmHg...…”

High cardiorespiratory fitness in early to late middle age preserves the cortical circuitry associated with brain-heart integration during volitional exercise

“…Importantly, experimental studies indicate that the IC, MPFC and HC are of particular relevance to HR control (Burns and Wyss 1985;Cechetto and Chen 1990;Fisk and Wyss 1997;Goswami et al 2012;Norton et al 2013;Oppenheimer et al 1992;Owens and Verberne 2001;Ruggiero et al 1987;Shoemaker et al 2015;Verberne 1996;Wong et al 2007;Yasui et al 1991). However, changes in regional brain activation patterns appear to be altered in older brains (Cabeza 2001;Norton et al 2015a). Beyond the age of 40 yr, older brains tend to show more symmetrical activation, either be-cause they have increased activation in a hemisphere that is less activated than in younger adults or because they show reduced activation in the areas most activated in younger adults.…”