 Cardiovascular System – Heart and Blood Vessels Topics in Human Pathophysiology Fall 2011 Gilead Drug Safety and Public Health

Outline  Heart  Conduction System and ECGs  Coronary Circulation  Cardiovascular Disease – diagnosis and treatment  Blood Vessels and Pressure  Structure of blood vessels  Blood pressure and regulation  Pulmonary arterial hypertension

 Coronary artery disease  Myocardial ischemia  Myocardial hypoxia  Myocardial infarct  Myocardial necrosis

From wikipedia

Age Male sex Heredity Smoking Diabetes mellitus Hypertension High cholesterol Obesity Lack of exercise

 Diagnosis  BP monitoring  Symptoms  ECG  Angiogram  Stress Test  Nuclear myocardial perfusion tests

 For myocardial perfusion imaging (MPI)  A 2A adenosine receptor agonist  Vasodilates coronary arteries as if exercising  Injected into blood stream prior to gamma camera scan  Can give a good indication of myocardial perfusion

Treatment – Coronary bypass surgery – Angioplasty – Stents – Cholesterol lowering agents – Anticoagulents – Antianginal medications

 For angina  Thought to inhibit a sodium ion channel in the cardiac muscle cells  Contraction of those cells might normally cause compression of cardiac blood vessels during diastole.  Can be taken with other anti-anginal meds  Very effective

Congestive Heart Failure  Heart becomes weak  Blood backs up in veins and capillaries  Fluid excess in tissues  Symptoms include shortness of breath, edema, difficulty breathing (especially when lying down,) difficulty exercising

Congestive Heart Failure  Causes:  cardiomyopathy  hypertension  lung disease  coronary artery disease  previous MI  valve disease

Blood Vessels and Pressure  Artery structure and function  Control over smooth muscle  Vascular Disease  Atherosclerosis  Pulmonary arterial hypertension

Figure 8.10

Vessel Wall Structure  Tunica intima – epithelium and connective tissue  Tunica media – smooth muscle  Tunica externa– connective tissue and epithelium

Figure 8.1

Arterial blood pressure and flow  Systolic and diastolic pressure  Regulatory factors  Cardiac  Sympathetic nervous system from vasomotor center of brain stimulates smooth muscle  Chemical messengers – hormones, paracrines

Components of Orthe Nervous System Figure 11.1 Organization of the Nervous System

Figure (1 of 2) Sympathetic and Parasympathetic Divisions of the Autonomic Nervous System

Figure (2 of 2) Sympathetic and Parasympathetic Divisions of the Autonomic Nervous System

Table 19.2 Hormonal Control of Blood Pressure

Pulmonary Arterial Hypertension

Pulmonary Arterial Hypertension (PAH)  Pulmonary arteries become narrowed causing decreased gas exchange and difficulty breathing  Causes R ventricular hypertrophy  Blood will back up in veins

Common causes of PAH Genetic defect Autoimmune diseases, such as scleroderma Congestive heart failure History of blood clot in the lung HIV infection Lung or heart valve disease Obstructive sleep apnea In many cases the cause is unknown- Idiopathic pulmonary arterial hypertension

Symptoms of PAH  Chest pain, usually in the front of the chest  Dizziness  Fainting  Fatigue  Leg edema  Light-headedness during exercise  Shortness of breath during activity  Weakness

Treatment for PAH  Letairis (ambrisentan)  Flolan or other prostacyclins  Bosentan (Tracleer)  Calcium channel blockers  Diuretics  Sildenafil (Viagra)  Supplemental oxygen  Surgical correction of defects  Lung transplant