Cardiovascular Pathophysiology (heart failure, valve disease, cardiomyopathies, pericardial disease, arrhythmias, shock introduction)

Pericardial effusion

Excess fluid between the two pericardial layers; severity depends on volume and rate of accumulation.

Cardiac tamponade

Life-threatening severe compression of the heart due to rapid or large pericardial effusion causing impaired filling and decreased stroke volume.

Cardiomyopathy

Disease of the heart muscle, with main types including hypertrophic and dilated.

Hypertrophic cardiomyopathy

Thickened interventricular septum and left ventricular wall causing outflow obstruction.

Dilated cardiomyopathy

Thinned, dilated ventricular walls with poor contractility, leading to reduced cardiac output.

Heart failure

Inability of the heart to pump adequate forward flow; key determinants include heart rate, stroke volume, preload, afterload, and contractility.

Ejection fraction (EF)

Percentage of ventricular volume ejected per beat; normal range approximately 60–70%.

BNP (B-type Natriuretic Peptide)

Hormone released in response to volume/pressure overload; used diagnostically (normal < 100 pg/mL).

Orthopnea

Shortness of breath when lying flat.

Pitting edema

Peripheral edema that retains an indentation with pressure.

Inotropes

Medications that increase contractility of the heart muscle.

Sinus bradycardia

Sinus rhythm with heart rate less than 60 bpm.

Atrial fibrillation (AFib)

Irregular heart rhythm characterized by absent P waves and high risk of thromboembolism; often requires anticoagulation.

Pulmonary edema

Acute condition with fluid accumulation in the lungs, commonly a presentation of left-sided heart failure.

Cardiac output

Volume of blood pumped by the heart per minute; calculated as stroke volume times heart rate.

Preload

Ventricular volume/pressure just before systole, influenced by venous return and residual volume.

Afterload

Pressure/resistance the heart must overcome to eject blood.

Contractility (inotropy)

Intrinsic strength of cardiac muscle contraction.

Jugular venous distention (JVD)

Visible neck vein distention indicating increased central venous pressure.

Left-sided heart failure

Failure of the left ventricle leading to pulmonary congestion, often due to myocardial infarction or hypertension.

Right-sided heart failure

Failure of the right ventricle leading to systemic venous congestion, often due to lung disease.

Telemeter strip

Telemetry EKG recording used to estimate heart rate by counting QRS complexes.

Six-second strip method

Counting QRS complexes in a six-second EKG strip and multiplying by 10 to approximate heart rate.

Regurgitation (insufficiency)

Incomplete closure of a valve leading to backward flow of blood.

Stenosis

Narrowing of a valve opening that restricts forward flow.

Shock

A life-threatening condition resulting from inadequate blood flow to the body's organs.