The study's aims are twofold: First, to examine physiological correlates of fear of physical activity (PA) and second, to examine correlates between fear of PA and interoceptive abilities in patients with chronic heart failure and healthy persons. Patients' fear of PA will be assessed via the "Fear of Activity in Situations - Heart Failure" (FActS-HF) questionnaire. The patient group will be split into two subgroups: One with high fear of PA and the second with low fear of PA based on FActS-HF scores. Fear of PA will be assessed via an adapted version of FActS-HF in a sample of healthy persons (control group). Each member of the high-fear-of-PA group will be individually age- and sex-matched with one member of the low-fear-of-PA group and control group. The participants of all three groups undergo the same experimental trials.

Aim 1: The "startle paradigm" will be used to investigate the physiological component of fear of PA. The startle paradigm is based on empirical observations that the startle reflex is larger after the priming with unpleasant stimuli and inhibited after the priming with pleasant stimuli. The participants will be primed with various words including those words associated with physical activity that are expected to be unpleasant in patients with high fear of PA. The startle reflex will be triggered by air puffs on the eyes (startle probes) and measured via facial electromyography (EMG). We assume that startle responses primed with PA related words are stronger in patients with high fear of PA compared to the other groups.

Aim 2: Interoceptive accuracy will be assessed via the "Schandry test" and interoceptive awareness will be assessed via the "Multidimensional Assessment of Interoceptive Awareness" (MAIA) questionnaire. During the Schandry test the participants will be instructed to subjectively count their heart rate without any aid or tools. The heart rate will be objectively measured at the same time via ECG. A high congruence of the objective and subjective results indicates a high interoception ability, and is assumed to be correlated with fear of physical activity. Additionally, we expect the MAIA and FActS scores to be correlated.

Inclusion Criteria:

• Clinical diagnosis of Heart Failure stage B or C (Hunt et al., 2005), or: New York Heart Failure classification II to IIIb

  1. Systolic dysfunction: left ventricular ejection fraction < 45% in the last 6 month
  2. Diastolic dysfunction: left ventricular ejection fraction >= 45% in the last 6 month

Exclusion Criteria:

• complex ventricular arrhythmias
• acute myocarditis
• symptomatic cardiac valve stenosis
• instable angina pectoris
• other severe diseases, that impair physical activity (e.g. advanced stages of cancer)
• insufficient language skills in German to answer the questionnaires
• insufficient cognitive skills to answer the questionnaires

The study population will consist of adult patients with diagnosed chronic heart failure of all underlying diagnoses. Patients have to be outpatients at time of study participation. They will be recruited in primary care clinics, and heart failure outpatient clinics in Germany. For the control group healthy volunteers without a chronic heart failure are recruited.