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Chapter 20. The Heart. Position of the Heart. Mediastinum Pericardium Epicardium Myocardium Endocardium. Heart Surface. Human heart. Heart Posterior. Heart Interior. Human Heart Interior. Surface of Valves. Valves. Circulation. Circulation. Coronary Arteries. The Echo Image.
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Chapter 20 The Heart
Position of the Heart Mediastinum Pericardium Epicardium Myocardium Endocardium
Pacemakers • Located in the right chest wall, a catheter is threaded through the subclavian vein, into the brachiocephalic vein, into the superior vena cava , then into the right atrium. • The pacemaker overrides the impulse from the SA node.
P= wave from SA node through atriaQRS = ventricular depolarizationT wave = ventricular repolarizationP-Q interval = time from atria contraction to beginning of ventricular contraction.Q-T interval = ventricular depolarization to repolarization.
Cardiac Output CO = SV x HR SV = ml/beat HR = Heart Rate
Cardiac Output Affected By • Frank-Starling Law / Marey’s Law • Cardiac Reserve (Max CO – CO at rest) • Contractility (hormones, drugs, sympathetic reactions, etc. • Afterload (remaining blood in ventricles) • Congestive heart failure
Regulation of Heart RateAffected/Monitored by: • Cardiovascular center (sympathetic and parasympathetic systems) • Proprioceptors • Chemoreceptors • Baroreceptors • Blood pH • Hormones • Ions • Age, gender, temp, etc.
Risk Factors for CAD • High blood cholesterol • High blood pressure • Smoking • Obesity • Diabetes mellitus • Type “A” personality • Sedentary lifestyle
Terms to Know • Fossa Ovalis • Coronary artery disease • Arteriosclerosis • Atherosclerosis • PTCA • Ischemia • Myocardial infarction
More Terms • Hypoxia • Angina pectoris • Coarctation of the aorta • Arrhythmia • Heart Block • Flutter and fibrillation • Bradycardia and tachycardia
More Terms • Cardiac arrest • Cardiomegaly • Cor pulmonale • Palpitation • Asystole • Endocarditis / myocarditis • Mitral valve prolapse • Auscultation