Unit
- Heart structure: The heart consists of four chambers: right atrium, right ventricle, left atrium, and left ventricle. The atria receive blood returning to the heart, while the ventricles pump blood out. The septum separates the left and right sides, preventing mixing of oxygenated and deoxygenated blood.
- Cardiac valves: Four valves ensure unidirectional blood flow. The tricuspid and mitral valves are atrioventricular; the pulmonary and aortic valves are semilunar. Valve disorders such as stenosis or regurgitation can impair cardiac output and require careful monitoring during PT programs.
- Coronary circulation: The heart receives its own blood supply through the left and right coronary arteries, which branch from the aorta. Blockages in these vessels cause myocardial ischemia and infarction, directly affecting exercise tolerance and rehabilitation strategies.
- Cardiac cycle phases: The cycle includes systole (contraction) and diastole (relaxation). During systole, ventricles eject blood; during diastole, they fill. The timing and efficiency of these phases are measured by heart rate, stroke volume, and ejection fraction, all key metrics in PT assessment.
- Electrical conduction system: The sinoatrial node initiates impulses, followed by the atrioventricular node, bundle of His, and Purkinje fibers. This system coordinates contraction timing. Abnormalities like arrhythmias directly impact exercise prescription and safety monitoring.
- Blood flow dynamics: Blood travels from the right side to the lungs for oxygenation, returns to the left side, and is pumped to the body. Resistance, pressure, and vessel diameter influence flow. PT interventions must consider these factors to avoid adverse events during activity.
- Cardiac output regulation: Cardiac output equals heart rate times stroke volume. The autonomic nervous system adjusts output via sympathetic and parasympathetic input. Understanding regulation helps PT professionals choose appropriate exercise intensities for cardiac patients.
- Heart-lung interaction: The cardiovascular and respiratory systems work together to deliver oxygen. Conditions like chronic obstructive pulmonary disease complicate cardiac rehab. A thorough understanding of this interdependence supports comprehensive patient care planning.
- Myocardial oxygen demand: Myocardial oxygen demand is determined by heart rate, contractility, and wall tension. During exercise, demand increases, and if supply is limited by coronary artery disease, ischemia can occur. PT professionals must monitor for signs of exertional intolerance and adjust intensity to maintain balance between supply and demand.
- Exercise blood pressure response: During dynamic exercise, systolic blood pressure normally rises while diastolic pressure remains stable or decreases slightly. An exaggerated hypertensive response or a drop in systolic pressure during exertion may indicate cardiovascular risk and warrants immediate evaluation before continuing therapy sessions.
- Cardiac medications impact: Beta blockers reduce heart rate and contractility, while vasodilators lower afterload. Diuretics decrease preload and can cause electrolyte imbalances. PT professionals must understand these effects because they influence exercise responses, vital sign interpretation, and session timing relative to medication schedules.
- Heart failure pathophysiology: Heart failure involves reduced ventricular pumping capacity or impaired filling, leading to fluid retention and decreased exercise tolerance. Patients often present with fatigue, dyspnea, and peripheral edema. Rehabilitation focuses on gradual aerobic conditioning, breathing strategies, and energy conservation techniques to improve functional capacity.
Scope of Practice
Role: Physical Therapy Coordinator in Inpatient Cardiac Rehab
Within scope:
- Reviewing patient cardiac history and current medications before session planning
- Measuring baseline heart rate and blood pressure using automated monitors
- Selecting appropriate exercise modalities based on physician clearance and risk stratification
- Educating patients on symptom recognition and activity pacing
- Documenting vitals and responses in electronic health records
Outside scope:
- Interpreting diagnostic cardiac imaging or electrocardiograms independently
- Adjusting cardiac medications or recommending dosage changes
- Performing invasive hemodynamic monitoring or catheter-based interventions
- Diagnosing new cardiac conditions or arrhythmias
- Prescribing exercise without a physician-approved plan of care
Quick Revision
- The heart's four chambers and valves maintain unidirectional blood flow, with coronary arteries supplying the heart muscle.
- The cardiac cycle and electrical conduction system determine heart rhythm and output, key for exercise prescription.
- PT coordinators assess vital signs and select exercises within their scope, but cannot interpret ECGs or adjust medications.
- Understanding heart-lung interaction supports safe rehabilitation for patients with comorbidities.