Cardiac Tests and Procedures

• Cardiac tests and procedures include:
• Electrocardiogram (ECG)
• Cardiac enzymes or biomarkers
• Chest X-ray (CXR)
• Echocardiograms
• Cardiac imaging
• Computed tomography angiography (CTA) or Cardiac MRI
• Coronary CT Calcium Score (CAC)
• Stress tests
• Cardiac catheterization
• Angioplasty
• Percutaneous intervention
• Coronary arterial bypass grafts (CABG) surgery
• Valve replacement or repair
• Holter monitors and event monitors
• Electrophysiology (EP) study
• Abdominal ultrasound or CT scan
• Ankle brachial index (ABI)
• Lower extremity angiography
• Lower extremity venous ultrasound, venous Doppler ultrasound of lower extremity
• Tilt table test

Next Best Tests

• A 55-year-old male presenting to the emergency department with chest pain should have an EKG
• A 55-year-old female with a positive stress echo test should have angiography
• A 55-year-old male presenting to the emergency department with shortness of breath should have a CXR
• A 55-year-old male with shortness of breath, weight gain, elevated JVP, S3, bilateral lower extremity edema, and CXR findings indicative of cardiomegaly and pulmonary congestion should have an echo
• A 55-year-old male with a new systolic murmur should have an echo
• A 55-year-old male with an abdominal pulsatile mass should have a CT or ultrasound of the abdomen
• A 55-year-old diabetic male with calf pain during walking and diminished pulses should have an ABI
• A 55-year-old male presenting to the emergency department with chest pain and normal EKG, CXR, and serial troponins should have a stress test
• Coronary artery calcium scores can be used to evaluate if patients should be placed on a statin for primary prevention
• A 55-year-old female presenting with palpitations should have an EKG
• A 55-year-old female presenting after an episode of syncope with normal EKG and echocardiogram should have a tilt table test or event monitor
• A 55-year-old male presenting with chest pain after a motor vehicle accident and normal EKG, CXR, and troponins should have CT angiography or echo to rule out aortic dissection or cardiac tamponade
• A 55-year-old male with new-onset swelling and pain of the right lower extremity with present dorsalis pedis and posterior tibial pulses should have an ultrasound

Electrocardiogram (ECG)

• Indications include:
• Suspected acute coronary syndrome/myocardial infarction (MI) with T wave inversion, ST segment elevation, or Q waves
• Suspected tachyarrhythmias or bradyarrhythmias, including AV nodal blocks
• Suspected atrial or ventricular enlargement
• Evaluation of the heart's axis
• Bundle branch blocks
• Suspected hyperkalemia, hypokalemia, hypercalcemia, hypocalcemia, hypothermia, digoxin toxicity, or pulmonary embolism pattern

Cardiac Enzymes/Biomarkers

• Troponin I or T (cTnl or cTnT) should be checked every 3-6 hours for 6-12 hours
• High-sensitivity troponin (hs-cTn) I or T should be checked every hour for 1-3 hours
• The rise and fall of troponin levels are important in diagnosing myocardial infarction, but there is a delay in the rise of troponin after an MI
• The results of cardiac biomarkers should not delay sending patients with acute ST-elevation MI to the cardiac catheterization lab
• False positives for elevated troponin can occur with pulmonary embolism, myocarditis, takotsubo cardiomyopathy, chronic kidney disease, or heterophile antibodies
• False negatives for troponin can occur with excessive biotin use
• Creatine kinase (CK) is found in all muscles, and CK-MB is more specific for the heart but is not commonly used anymore
• Indications include suspected acute coronary syndrome (ACS) if EKG is non-diagnostic, prompting multiple troponin tests

Chest X-Ray (CXR)

• Useful for assessing aortic dissection/aneurysm.
• Useful for assessing cardiogenic pulmonary edema.
• Indications include cardiac disease, aortic aneurysm, aortic dissection, heart failure, and pericardial effusion.
• Pericardial effusion does not show edema like in heart failure.

Echocardiogram

• Diagnoses and determines the severity of valvular disease.
• Assesses ventricular function of systole (ejection fraction) and diastole.
• Detects pericardial effusion.
• Diagnoses and assesses congenital heart disease.
• Looks for thrombus in the atria or ventricle.
• Detects infective endocarditis (vegetations on leaflets).
• Assesses cardiomyopathies (restrictive, obstructive, and dilated).
• Detects aortic dissection.

Types of Echocardiograms

• Transthoracic Echocardiogram.
• Transesophageal Echocardiogram: requires patient to be NPO.
• Stress Echocardiogram: looks for wall motion abnormalities during stress and rest.
• Fetal Echocardiogram.
• Three-Dimensional Echocardiogram.

Radionuclide Ventriculography or Radionuclide Angiography (MUGA Scan)

• Nuclear medicine scan
• Estimates ejection fraction in morbidly obese patients if echocardiogram does not give good window images

Cardiac Imaging

• Computed tomography angiography (CTA) or Cardiac MRI.
• Detects aortic aneurysms, aortic dissection, pulmonary embolism, pericarditis, congenital heart disease, valvular heart disease, heart failure, or cardiac tumors

Coronary Artery Calcium (CAC) Score

• Calcium scoring can determine 10-year risk of cardiovascular event
• 0 = <1% risk, interpreted as very low risk
• 1-99 = 4% risk, interpreted as low risk
• 100-399 = 13% risk, interpreted as moderate risk
• ≥400 = 24% risk, interpreted as high risk
• A low score might result in not starting cholesterol lowering medications
• A high score determines if patient should take cholesterol medication

Stress Tests

• Used to diagnose coronary artery disease (CAD) or inducible arrhythmias

Stress Test Names

• Standard exercise stress test including exercise tolerance test, stress EKG or ECG, and treadmill test
• Imaging stress test including exercise or pharmacologic stress echocardiogram, myocardial perfusion imaging/nuclear stress test/sestamibi stress test, positron emission tomography (PET), and single photon emission computed tomography (SPECT)

Cardiac Catheterization

• Diagnoses and treats coronary artery disease (CAD)
• Procedures include balloon angioplasty and percutaneous stent with balloon angioplasty (PCI)
• Access can be via the radial artery or traditional catheterization

Coronary Artery Bypass Graft (CABG) Surgery

• Sites of blockage are targeted by bypass grafts
• Internal mammary artery is often used, but saphenous vein and radial artery bypasses are alternative options.

Indications for CABG

• Left main trunk artery stenosis
• Poor left ventricular (LV) function
• Significant 3-vessel CAD or 2-vessel disease involving proximal left anterior descending artery (LAD)
• Diabetes mellitus (DM) with focal stenosis in more than one vessel
• Multiple narrowing in multiple coronary artery branches

Valve Repair or Replacement

• Can be surgical or interventional
• Transfemoral transcatheter aortic valve replacement (TAVR)
• Transapical TAVR
• Transaortic (TAO)
• Open heart surgery (AVR)
• Minimal incision valve surgery (MIVS)

Heart Monitors

• Holter monitor, Event Monitor, and Ambulatory Cardiac Monitors
• Used to diagnose suspected arrhythmias (presenting with syncope, pre-syncope, palpitations, etc.) if initial ECG is negative

Electrophysiology (EP) Study

• Used in diagnosing ventricular arrhythmias in a patient with syncope and negative work-up
• Determines the site of block in patients with abnormal atrioventricular conduction
• Risk stratification for sudden cardiac death:
• Nonsustained ventricular tachycardia in heart failure patients with an ejection fraction <40%. Induction of sustained ventricular tachycardia or ventricular fibrillation is a class I indication for ICD implantation
• Helpful in evoking and treating Wolff-Parkinson-White (WPW) syndrome

Abdominal Ultrasound or CT Scan

• Cardiovascular indications including diagnosis of aortic abdominal aneurysm (AAA) if > 3 cm

Ankle-Brachial Index (ABI)

• ABI = ankle blood pressure / brachial blood pressure
• Indication to evaluate patients with suspected Peripheral Arterial Disease (PAD)
• Can be used for screening for patients over 60 or patients over 50 who are diabetic or who smoke

Lower Extremity Angiography

• Indications include definitive diagnosis of PAD and interventional treatment of PAD
• It is an invasive test with catheter and injecting dye
• Lower Extremity Ultrasound: indications include suspected deep vein thrombosis (DVT) in extremity swelling, uses Doppler US to look for artery disease

Tilt Table Test

• Indications include:
• Orthostatic hypotension
• Postural Orthostatic Tachycardia Syndrome (POTS)
• Unexplained lightheadedness, falls, frequent episodes of syncope

Point of Care Ultrasound (POCUS)

• Helps narrow down differential diagnoses and guide treatment by addressing specific clinical questions
• B-Lines indicate pulmonary edema if 3 or more are present in a visual field
• Pericardial effusion, diastolic right ventricular collapse, systolic right atrial collapse, plethoric inferior vena cava lacking respiratory variation, and exaggerated respiratory cycle changes in mitral and tricuspid valve in-flow velocities indicate cardiac tamponade
• Hypokinesis indicates left ventricular or right ventricular failure
• Helps evaluate the presence of severe valvulopathies