The differential effects of positive versus negative emotions on autonomic nervous system activity are insufficiently understood. This study examined the role of acute mood responses and central nervous system activity on heart rate variability (HRV) using 5-min event recall tasks (happiness and anger recall) and a 5-min Stroop Color Word Test (SCWT) in 20 healthy individuals (mean age 25±4 years, 55% female). HRV was measured in high frequency (HF) and low frequency (LF) domains, and frontal brain activity using electroencephalography (EEG) in the alpha frequency band in F3 and F4. Happiness Recall resulted in increased LF-HRV (p=0.005) but not HF-HRV (p=0.71). Anger Recall did not change HRV (p-values>0.10). The SCWT produced decreases in HF-HRV (p=0.001) as well as LF-HRV (p=0.001). The magnitude of feeling "happy" during Happiness Recall was positively correlated with ΔHF-HRV (p=0.050), whereas an incongruent mood state ("frustrated") was associated with smaller ΔHF-HRV (p=0.070). Associations between frontal EEG activation and HRV responses were mostly non-significant, except for increased right frontal activation during Happiness Recall which was associated with a decrease in LF/HF ratio (p = 0.009), It is concluded that positive and negative mood induction result in differential HRV responses, which is related to both task valence and the intensity of task-induced emotions.

The relation of primary cognitive appraisals to cardiovascular reactivity, affect, task engagement, and perceived stress was examined in 56 men (ages 18-29). Systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate, preejection period, stroke index, cardiac index, and total peripheral resistance were assessed at rest and during performance of a computerized mental arithmetic task. Extending on prior investigations, threat and challenge appraisals were assessed independently from one another and from secondary appraisals. Positive and negative affect, task engagement, and levels of perceived stress were also assessed. Results indicated that threat (R2 =.08, p =.01), challenge (R2 =.14, p =.003), and their interaction (R2 =.11, p =.006) independently predicted DBP reactivity; DBP responses were greatest among participants with a high threat/low challenge pattern of appraisal. Threat appraisals predicted greater negative affect (R2 =.32) and perceived stress (R2 =.48), whereas challenge appraisals were related to greater positive affect (R2 =.44) and task engagement (R2 =.40, ps <.0001). Greater positive affect was correlated with increased SBP and DBP reactivity, and greater levels of task engagement with increased DBP response (ps < or = .002). Results suggest that primary cognitive appraisals are more potent predictors of affect and task engagement than cardiovascular reactivity.

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Background-Innervation is a critical component of arrhythmogenesis and may present an important trigger/substratemodifier not used in current ventricular tachycardia (VT) ablation strategies. Methods and Results-Fifteen patients referred for ischemic VT ablation underwent preprocedural cardiac 123 I-metaiodobenzylguanidine ( 123 I-mIBG) imaging, which was used to create 3-dimensional (3D) innervation models and registered to high-density voltage maps. 3D 123I-mIBG innervation maps demonstrated areas of complete denervation and 123 I-mIBG transition zone in all patients, which corresponded to 0% to 31% and 32% to 52% uptake. I-mIBG transition zones were <0.5 mV, 0.5 to 1.5 mV, and >1.5 mV in 35%, 36%, and 29%, as well as 35%, 35%, and 30%, respectively (P>0.05). Successful ablation sites were within bipolar voltage-defined scar (7%), border zone (57%), and areas of normal voltage (36%), but all ablation sites were abnormally innervated (denervation/ 123 I-mIBG transition zone in 50% each). Conclusions- 123I-mIBG innervation defects are larger than bipolar voltage-defined scar and cannot be detected with standard voltage criteria. Thirty-six percent of successful VT ablation sites demonstrated normal voltages (>1.5 mV), but all ablation sites were within the areas of abnormal innervation. 123I-mIBG innervation maps may provide critical information about triggers/substrate modifiers and could improve understanding of VT substrate and facilitate VT ablation. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique Identifier: NCT01250912.

Previously, rats fed a high-fat liquid diet (HF) ad libitum consumed more kilocalories and had greater weight gain than rats fed a liquid high-carbohydrate diet (HC) of equivalent energy density (Warwick, Z. S., and H. P. Weingarten. Am. J. Physiol. Regulatory Integrative Comp. Physiol. 269: R30-R37, 1995). The present series of experiments sought to clarify the behavioral expression of HF hyperphagia by comparing HF and HC with regard to meal size and magnitude of postingestive satiety effect. Meal size of HF was greater than HC at 2.3 kcal/ml and also when diets were formulated at 1.15 kcal/ml. In a preload-test meal paradigm, an orally consumed HF preload was less satiating than a calorically equivalent HC preload across a range of preload volumes and intermeal intervals. Sensory-specific satiety was ruled out as an explanation of the relatively greater intake of test meal after an HF preload meal; an intragastrically delivered HF preload was less satiating than intragastric HC. Furthermore, a fat (corn oil emulsion) preload was less satiating than a carbohydrate (sucrose) preload when an evaporated milk test meal was used. These findings indicate that hyperphagia on an HF diet is expressed in increased meal size and decreased intermeal interval.