The purpose of this study is to examine the role of every day experiences as they relate to coronary artery disease (CAD).

CAD is the most common setting in which sudden cardiac death (SCD) occurs. SCD is the leading cause of death in the U.S.

In this study we propose to test the following in patients with CAD:

• Determine whether experiences assessed randomly throughout the day are associated with changes in the blood supply to your heart muscle as measured by electrical recordings from your chest.
• Determine whether typical daily experiences are associated with changes in the recovery time portion of your heart beat cycle as measured by electrical recordings from your chest.
• Determine whether changes in the recovery time portion of your heart beat cycle associated with typical daily experiences occur exclusively with changes in the blood supply to your heart muscle.
• Determine whether typical daily experiences influences blood supply and recovery time based on the severity and presence of CAD (when comparing CAD patients to healthy subjects).

KEY INCLUSION CRITERIA: LOW RISK CAD SUBJECTS, EJECTION FRACTION >35%

• Proficient in English
• At least 21 years of age or older
• Stable coronary artery disease
• Willing to participant in 3 days of Holter monitor recordings and respond to surveys on a study provided smartphone

KEY EXCLUSION CRITERIA: LOW RISK CAD SUBJECTS

- Presence of bundle branch block evident on ECG

KEY INCLUSION CRITERIA: HIGH RISK CAD Subjects, Ejection Fraction <35%

• Proficient in English
• 21 years of age or older
• Have stable coronary artery disease with a documented previous myocardial infarction
• Recent ECHO, MUGA or angiography (< 5year old) reflecting a left-ventricular ejection fraction <35%
• Single or dual chamber ICD, with a back up rate of ventricular pacing at < 45 bpm
• Willing to wear a Holter monitor for 3 days and respond to surveys on a study provided smartphone

KEY EXCLUSION CRITERIA: HIGH RISK CAD, Ejection Fraction <35%

• An implanted cardiac resynchronization pacemaker with ICD (CRT-D)
• Heart rhythm artificially continuously paced
• Presence of a bundle branch block evident on any ECG

KEY INCLUSION CRITERIA: OLDER HEALTHY COMPARISON

• Proficient in English
• 51 years of age or older
• No history and evidence of ischemic heart disease
• Normal screening ECG without evidence for rhythm abnormalities, conduction abnormalities, hypertrophy, or other pathologies
• Age matched within 5 years to CAD patients
• Negative treadmill/bicycle exercise test
• Willing to wear a Holter monitor for 3 days and respond to surveys on a study provided smartphone

KEY EXCLUSION CRITERIA: OLDER HEALTHY COMPARISON

• History of ischemic heart disease (CAD),prior myocardial infarction
• History of cardiac disease

KEY INCLUSION CRITERIA: YOUNGER HEALTHY (ENROLLMENT CLOSED)

• Proficient in English
• 21 to 50 years of age
• Normal screening ECG without evidence for rhythm abnormalities, conduction abnormalities, hypertrophy, or other pathologies
• Willing to wear a Holter monitor for 3 days and respond to surveys on a study provided smartphone

KEY EXCLUSION CRITERIA: YOUNGER HEALTHY

• History of ischemic heart disease (CAD), prior myocardial infarction
• History of cardiac diseases
• Abnormal ECG

University of Arizona Medical Center (overhead TV monitors); Cardiology Clinics; Community Centers; Primary Care Clinics; Pima Heart; Desert Cardiology; Referrals from study participants, Craig's List