Cardiac Diagnostic Testing and Procedures

Diagnostic Testing and Procedures

• Diagnostic testing and procedures encompass both invasive and non-invasive methods for evaluating cardiac function and identifying potential issues.
• Golda Widawski, PT, DPT will discuss these topics between February 10-18, 2025

Objectives

• Indications and risks of cardiac catheterization will be explained.
• The general process for cardiac catheterization and PT considerations will be described.
• The use of electrophysiology studies will be explained.
• Types of non-invasive cardiac testing will be identified and explained, this includes: EKG and telemetry, Holter, Echocardiogram (TTE vs TEE), Chest X-ray, PET scan, CT scan, MUGA scan, MRI.
• Cardiac perfusion testing (thallium stress test) will be described, including how to differentiate between ischemic and infarcted areas of the heart.
• The basics of cardiac viability testing will be covered.
• An understanding of different invasive lines for monitoring patients, including their general purpose and impact on PT, will be demonstrated.
• A basic understanding of pertinent lab values and potential implications for PT will be demonstrated.

Invasive vs Non-Invasive Testing

• Invasive tests include catheterization, EPS (Electrophysiology Studies), lines (Cordis, Swan Ganz, Arterial Line, Central Venous Pressure (CVP) Line), and labs.
• Non-Invasive tests include EKG/ECG, Holter, Echocardiography, PET scan, CT, CXR, MUGA, MRI, Thallium, and Exercise.

Catheterization

• This involves insertion of a catheter into the femoral artery, advanced via fluoroscopy.
• Contrast dye is released into the ventricles or coronary arteries, and the flow of dye is recorded (angiogram).
• Bed rest for about six hours usually follows this procedure.
• Goals of catheterization are to establish or confirm a diagnosis, determine the extent/severity of CAD or valve disease, and help establish a plan of care/treatment.
• Data obtained include cardiac output, blockage of coronary arteries, heart pressures, LVEF (Ejection Fraction), muscle function, and valve function.
• Indications include cardiac arrest or ventricular fibrillation, pulmonary edema, or intolerance of medical therapy for angina.
• Exercise/stress tests are also a part of the indicators.
• Risks associated with catheterization exist.
• PT considerations include patient bed rest for about 6 hours post-procedure, potential hematoma formation, and discomfort at the cath site.

Electrophysiology Studies (EPS)

• EP Studies are used to diagnose arrhythmias, evaluate the efficacy of medical therapy, and predict the risk for sudden death while assessing the need for pacemakers and ICDs.
• The approach is similar to cardiac catheterization.
• A catheter is brought into the right atria/ventricle to try and stimulate arrhythmias, with very specific areas being tested.
• Treatment is based on the EP study, involving medication vs ablation vs pacemaker vs AICD implantation.
  • Used as an ablation procedure.

Non-Invasive Testing: EKG

• Resting EKG detects abnormal rate & rhythm, conduction abnormalities, hypertrophy of ventricles, myocardial ischemia, and electrolyte & medication effects.
• Single Lead detects rate & rhythm, gross myocardial ischemia, and conduction abnormalities.

Holter Monitor

• This involves 24+ hr EKG monitoring.
• Available with wires or wireless.
• The holter monitor is useful to diagnose and manage arrhythmias and symptoms.

Echocardiogram

• TEE (Transesophageal Echocardiogram) is invasive
• TTE (Transthoracic Echocardiogram).
• TTE is used pre/post exercise (test).
• Pulses of reflected ultrasound is to assess heart's function and structures, assess the patency of the coronary arteries, and assess SV, CO, EF (at rest and during exercise).
• Modalities include Doppler, Color Flow Doppler, 2-D, 3-D, and M-Mode..

Chest X-Ray (CXR)

• Used to assess heart size, pulmonary edema, and pulmonary artery size.
• This is a useful tool to evaluate CHF and Interstitial/perivascular/alveolar edema.

PET Scan (Positron Emission Tomography)

• This measures metabolic function and blood flow to the heart.
• Can reveal size, shape, position, & some function of the heart.
• Can be used to diagnose heart problems AND show areas where there is poor blood flow to the heart.
• Used to detect jeopardized myocardium.

CT Scan (Computed Tomography)

• With contrast dye = coronary CT angiography (CTA).
• Used for Coronary Calcium Scan.
• Used to identify problems with aorta, PE or other problems with pulm veins, problems with heart function or valves, or pericardial disease.
• Can identify results of CABG and assess patency of grafted arteries.

MUGA (Multigated Acquisition Imaging)

• This shows how well the heart is pumping with each heartbeat.
• May be done while resting or exercising or both.
• MUGA measures LVEF and utilizes electrical activity of the heart via EKG.

MRI (Cardiac MRI)

• MRI creates still & moving pictures of heart & major blood vessels.
• Gets pictures of beating heart to look at structure & function.
• Is used to assess & diagnose: CHD, Damage from MI, Heart failure & valve problems, Congenital heart defects, Pericarditis, or Cardiac tumors.
• Assesses regional blood flow problems and may use contrast (gadolinium).

Thallium Cardiac Perfusion Testing (Thallium Stress Test)

• Good at predicting risk of recurrent MI and assesses acute cardiac ischemia during exercise stress test.
• Looks at perfusion (blood flow to myocardium) and cell membrane integrity (at rest and during activity).
• The radiopharmaceutical is injected via IV, often at rest AND once exercising at the desired level.
• Cells need to be both perfused and metabolically intact to collect the thallium.
• Scanned immediately post exercise and 2-4 hours later.
• Cold spots (where not absorbed/collected) indicate irreversibly damaged or ischemic/reversible areas. Areas of decreased blood flow have less thallium uptake.
• Areas that are not perfused immediately post-exercise but re-perfuse after 2-4 hours = ISCHEMIA.
• Areas that remain not perfused after 2-4 hours = INFARCT.
• Is used to assess optimal treatment & effectiveness of treatment, cause of new chest pain, how heart is pumping, or may be used to diagnose CAD. Also used to assess cardiac size or cardiac function post MI.
  • Is done prior to initiating exercise program or having surgery-if at high risk for heart disease or complications.
• Pharmacologic Stress Testing:
• Performed with medications to mimic exercise for patients who cannot tolerate upright exercise or cannot achieve at least 85% of their predicted max HR.
• These medications include Persantine Adenosine and Dobutamine. -These medications increase the work of the heart.

Cardiac Viability Testing

• This is done to examine heart's metabolism.
• It assesses how blood is flowing to heart muscle, looks to look for damaged heart muscle and assess how well heart is pumping (ventricular function scanning).
• Is used to asses sFeasibility of revascularization interventions. Usually 2 sets of pictures are taken during nuclear heart scan:
• 1st Set after stress test while heart is beating fast.
• 2nd Set taken later-while heart is at rest & beating at normal rate.
• Two main types: SPECT (Single Photon Emission Computed Tomography) or PET (Cardiac Positron Emission Tomography).
• PET takes clearer picture through thick layers of tissue & shows if CHD is affecting more than one cardiac vessel better.
• PET Allows visualization of relative distribution (SPECT) and absolute distribution (PET) of myocardial blood flow.

Lines

-Sheath Introducer: Placed in blood vessel as entryway for other lines to be placed. -Cordis = brand of introducer.

Swan Ganz Catheter

• Introduced by Drs. Swan and Ganz in the 1960’s.
  • Involves passage of catheter into neck to the right side of the heart & arteries leading to monitor heart's function and blood flow
• All data provides direct information relevant to cardiac function.
• Abnormal results may indicate:; Blood flow problems (heart failure, shock), * Heart valve disease
• Lung disease and/or Structural problem with heart (septal defect)

A- Line Arterial

• Indwelling catheter with Pressure transducer attached, to assess arterial Blood pressure
• Commonly placed in the radial artery, but may be placed in other arteries (axillary, femoral.) It is Indirectly measures cardiac performance via blood pressure and arterial blood gas information. Notes: Do not take manual blood pressures on the extremity.

Central Venous Pressure- CVP Catheter

• Catheter introduced-advanced into a vein and advanced to the superior vena cava/ or right atrium to Examine Blood volume Vascular tone and Venous return
• CVP Catheter’s allow Rapid administration of IV fluids etc. Note.

PT Considerations: Have care with mobilization with arterial lines, CVP and femoral ines Speak to doctors for orders- always avoid flexing extremities with lines

• Other assessments : Peripheral limb measurements, and consider these measurements: AB1- ankle brachial index, BMI-Body Mass Index, etc..