Heart Anatomy and Function

Heart Anatomy and Function

• The heart has four chambers: right atrium, right ventricle, left atrium, and left ventricle.
• Deoxygenated blood enters the right atrium via the inferior and superior vena cava.
• Blood passes from the right atrium through the tricuspid valve to the right ventricle.
• Blood exits the right ventricle through the pulmonary semilunar valve to the pulmonary artery.
• Blood travels to the lungs for oxygenation.
• Oxygenated blood returns via the pulmonary vein to the left atrium.
• From the left atrium, blood passes through the bicuspid (mitral) valve to the left ventricle.
• Blood exits the left ventricle through the aorta to the body.

Heart Sounds and Electrical Activity

• S1 heart sound results from the opening and closing of the atrioventricular (A-V) valves.
• The sinoatrial (SA) node is the heart's pacemaker
• Normal Sinus Rhythm is 60-100 beats per minute.
• Bradycardia is a heart rate below 60 beats per minute.
• Tachycardia is a heart rate above 100 beats per minute.

EKG/ECG Components

• P wave represents atrial depolarization (contraction).
• QRS complex represents ventricular depolarization (contraction).
• T wave represents ventricular repolarization (relaxation).
• QT interval is the time required for ventricular depolarization and repolarization.

Abnormal Heart Sounds and Conditions

• S3 and S4 are abnormal heart sounds indicating ineffective valve closure.
• A heart murmur is caused by turbulent blood flow.
• STEMI is an ST-Elevation Myocardial Infarction, indicating a heart attack.
• Non-STEMI is a heart attack without ST elevation.

EKG Abnormalities

• Atrial fibrillation presents as a sawtooth pattern on an EKG.
• Atrial flutter also presents as a saw teeth pattern on an EKG.
• Hypokalemia can be indicated by a U-wave on an EKG.
• Hyperkalemia can be indicated by a tall T wave and a flat P wave on an EKG.

Diagnostic Procedures: Cardiac Catheterization

• Cardiac catheterization uses dye to visualize heart structures.
• Before the procedure, check for shellfish allergies.
• After the procedure, monitor for bleeding.
• Patients must lay flat without a closure device for 4-6 hours, and with a closure device for 2-4 hours.
• No flexion is allowed, but side-to-side movement is permitted post-procedure.
• Apply direct pressure if bleeding occurs (no time for sterile gloves).
• Sandbags may be used at the insertion site to prevent bleeding.

EKG vs. ECG

• EKG (Electrocardiograph) shows electrical activity.
• ECG (Echocardiograph) uses ultrasound to visualize valves.
• Transesophageal echocardiogram is an invasive procedure that requires informed consent.

Heart Failure: Right-Sided

• Signs and symptoms of right-sided heart failure include peripheral edema, dependent edema, and pitting edema.
• Hepatomegaly (enlarged liver) and splenomegaly (enlarged spleen) are also signs.
• Upper right and left quadrant abdominal pain may occur.

Heart Failure: Left-Sided

• Signs and symptoms of left-sided heart failure include atelectasis (collapsed lung).
• Orthopnea (trouble breathing when lying down), dyspnea, and pink frothy sputum may occur.
• Hemoptysis (blood in sputum) may also be present.

Vascular Conditions: Deep Vein Thrombosis (DVT)

• Risk factors for DVT include immobility, smoking, and oral contraceptive use.
• Treatment includes anticoagulants (heparin, warfarin, Coumadin) and thrombolytics.
• Monitor platelet levels during treatment.
• Do not restrict fluids.
• Elevate the affected limb.

Vascular Conditions: Peripheral Vascular Disease (PVD)

• PVD is an umbrella term including Peripheral Arterial Disease (PAD) and Peripheral Venous Disease (PVD).
• Peripheral Arterial Disease (PAD): Blood cannot flow down to extremities, resulting in pale, cold limbs and lack of hair growth; manage by keeping limbs dependent.
• Peripheral Venous Disease (PVD): Blood cannot return to the heart, resulting in swollen, red, warm limbs; manage by elevating limbs above heart level.

Other Vascular Conditions

• Raynaud's Phenomenon: Fingers appear pale/white/yellow, triggered by cold weather and stress; manage by avoiding cold, wearing gloves, reducing stress, and stopping smoking.
• Angina: Chest pain triggered by exertion and anxiety.
• Stable angina resolves with rest.
• Unstable angina persists even with rest.

CPR Guidelines

• Rate should be 100-120 compressions per minute.
• Ratio should be 30 compressions to 2 breaths.
• Switch rescuers every 2 minutes.
• When using an AED, first check the level of consciousness.

Medication-Related Information

• Digoxin: Used for atrial fibrillation; signs of toxicity include nausea and refusing food; first step is to check vital signs if toxicity is suspected.
• Polystyrene sulfonate: Used for hyperkalemia (high potassium).

Risk Factors and Prevention

• Heart Disease Risk Factors:
  • Non-modifiable: age, gender, ethnicity/race, family history.
  • Modifiable: hyperlipidemia (high cholesterol), obesity, smoking.
• Infective Endocarditis: Risk factors include poor oral hygiene and untreated strep throat; prevent with antibiotics before dental procedures.

Additional Conditions

• Endocarditis: Inflammation of the heart muscle.
• Splinter hemorrhages: Black lines under fingernails are a sign of endocarditis.
• Essential Hypertension: Controlled through lifestyle modifications.