Cardiovascular System Disorders and Treatments

Disorders of the Cardiovascular System

Heart Transplantation

• First successful human heart transplant: 1967.
• Approximately 3500 heart transplants performed annually, about half in the United States.

Left Ventricular Assist Device (LVAD)

• A mechanical pump that supports heart function in patients with weakened hearts.
• Function: Blood from the left ventricle flows into the LVAD, which then pumps it to the aorta, assisting in systemic circulation.
• Components:
  • LVAD (implanted pump).
  • External control unit.
  • Batteries.
  • Cable connecting the internal LVAD to the external control unit through the abdomen.
• Mobility: Allows patients to be fully mobile.

Blood Pressure

• Definition: The force with which blood pushes against the artery walls.
• Systolic Pressure:
  • Measures cardiac output.
  • Represents the pressure in the arterial system at its highest during the contraction phase of the heart.
• Diastolic Pressure:
  • Measures peripheral resistance.
  • Represents arterial pressure at its lowest, between heart contractions (relaxation phase).
• Normal Blood Pressure (Adult Average): 120/70 mmHg. (millimeters of mercury)
  • Systolic: 120 mmHg
  • Diastolic: 70 mmHg

Hypertension

• Definition: High blood pressure.

• Blood Pressure Chart:

  • Normal: Less than 120 (systolic) / Less than 80 (diastolic).
  • Prehypertension: 120-139 (systolic) / 80-89 (diastolic).
  • High Blood Pressure Stage 1: 140-159 (systolic) / 90-99 (diastolic).
  • High Blood Pressure Stage 2: 160 or Higher (systolic) / 100 or Higher (diastolic).
  • Hypertensive Crisis: Higher than 180 (systolic) / Higher than 110 (diastolic).

• Ideal blood pressure: Less than 120/80 mmHg

• Complications of Hypertension:

  • Brain Stroke: Reduced blood supply leading to rapid loss of brain function.
  • Vision Loss: Hypertensive Retinopathy (damage to blood vessels in the retina).
  • Blood Vessel Damage: Atherosclerosis (artery-narrowing process).
  • Kidney Failure: Damaged blood vessels impairing blood filtration.
  • Heart Attack: Increased workload on the heart leading to thickening of the heart muscle.
  • Bone Loss: Increased calcium in urine leading to osteoporosis.

Congestive Heart Failure

• Mechanism: Ventricles unable to contract effectively, causing blood pooling in the heart.
• Symptoms:
  • Edema (swelling) in lower extremities.
  • Blood backing up into the lungs.
• Treatment (Rx):
  • Drugs to strengthen heartbeat.
  • Diuretics to reduce fluid accumulation.

Atherosclerosis

• Definition: Disease characterized by cholesterol-containing plaque accumulation inside arterial walls.
• Impact:
  • Interferes with blood flow by blocking the lumen of the blood vessel.
  • Can result in an embolus (free-floating blood clot) or thrombus (blood clot).

Myocardial Infarction (MI)

• Definition: Death of a portion of the heart muscle cells due to obstruction or blockage of a coronary artery.
• Symptoms:
  • Crushing pain or pressure in the chest.
  • Radiating pain in the left arm.
  • Nausea.
  • Clamminess.
  • Shortness of breath.
• Treatment:
  • Immediate medical care is critical.
  • Bedrest, oxygen, medication.
  • Morphine for pain relief, tPA to dissolve clot.
  • Anticoagulant therapy to prevent further clot formation.
  • Angioplasty and bypass surgery may be necessary.

Heart Murmur

• Definition: Abnormal heart sound, described as whooshing, fluttering, or humming.
• Indication: Often indicative of a heart abnormality such as stenosis (narrowing) of a heart valve or an incompetent heart valve resulting in regurgitation (backflow).
• Prolapse: Refers to when valve cusps are forced backward.

Echocardiogram

• A diagnostic test that uses ultrasound waves to create an image of the heart.
• Labels in the image:
  • LVPW(Left Ventricular Posterior Wall)
  • IVS(Interventricular Septum)
  • RV(Right Ventricle)
  • LV(Left Ventricle)
  • MV(Mitral Valve)
  • LA(Left Atrium)
  • Domed AV(Aortic Valve)

Artificial Valves

• Types: Tissue Valve and Mechanical Valve.

Angioplasty and Stents

• Angioplasty:
  • Reconstruction of a diseased coronary artery.
  • Procedure: A small balloon is inserted through the aorta and into a coronary artery. The balloon is inflated to flatten plaque mass and dilate the artery, improving blood flow.
• Stents:
  • Metal-mesh tubes that are stronger and permanent.
  • Inserted into the vessel to prevent further blockage after angioplasty.
• Process:
  • Balloon catheter is inserted into the artery.
  • Balloon is inflated to expand the stent.
  • Balloon is deflated.
  • Catheter is removed, leaving the stent in place to hold the artery open.

Coronary Artery Bypass Graft Surgery (CABG)

• Procedure: A healthy vein (often from the leg) is removed and attached before and after the coronary obstruction, creating an alternate route for blood supply to the myocardium.

• Heart-Lung Machine:

  • Pump returns oxygenated blood to the aorta, which delivers it to the rest of the body.

• Off-pump coronary artery bypass graft surgery:

  • Heart-stabilizing device
  • Sternal retractor
  • Vessel graft for blood flow to bypass blockage.

Varicose Veins

• Definition: Swollen, twisted, and sometimes painful veins.
• Cause: Pooling of blood due to faulty valves.
• Prevalence: More prevalent in women and individuals who stand for long periods.
• Risk Factors: Pregnant women.
• Complication: Thrombophlebitis (inflammation of a vein resulting from a clot in a vessel with poor circulation).
• Characteristics:
  • Deformed Valves
  • Abnormal Blood Flow
  • Dilated Vein
  • Thin wall of vein
  • Skin bulging

Hopkins History (Cardiovascular Related)

• 1897: Hormone Epinephrine discovered and named. First hormone to be discovered.
• 1933: William Kouwenhoven and colleagues discover that an electric shock can restore a normal rhythm to an irregularly beating heart. This work laid the foundation for cardiopulmonary resuscitation.
• 1944: Alfred Blalock and Vivien Thomas devise a surgical correction for tetralogy of Fallot which is also known as the “blue baby” operation.
• 1944: Cardiac Catheterization Is Used to Diagnose Heart Disease
• 1960: CPR is developed; chest compressions are found to be life-saving.
• 1980: First implantation of the automatic defibrillator in a human being.

Blue Baby Operation

• Surgical procedure to correct Tetralogy of Fallot. This pathology is also known as “blue baby” because a baby’s skin will look blue due to a lack of oxygen in the blood.