Cardiology diagnostic tests and procedures: Difference between revisions

Latest revision as of 14:43, 1 April 2025

Methods for diagnosing heart conditions

Diagnostic tests in cardiology are used to identify various cardiac conditions by evaluating heart structure, function, and electrical activity. These tests can be non-invasive or invasive and are used in both emergency and outpatient settings to aid in the diagnosis and management of cardiovascular disease.

Bedside Assessment[edit]

Medical History[edit]

Obtaining a thorough medical history is the first and most essential step in evaluating cardiac health. While some symptoms such as chest pain, dyspnea, or palpitations may point to significant heart disease, other symptoms may be absent or misleading. Consequently, history alone is rarely sufficient to confirm or rule out a cardiac condition.

Auscultation[edit]

Auscultation using a stethoscope allows clinicians to listen for normal and abnormal heart sounds, such as murmurs, gallops, and pericardial rubs. These may suggest underlying structural or functional abnormalities of the heart valves or chambers.

Laboratory Investigations[edit]

Blood Tests[edit]

Various blood tests help in the evaluation of cardiovascular risk and myocardial injury:

Lipid profile – Total cholesterol, LDL, HDL, triglycerides
C-reactive protein – Marker of inflammation
Homocysteine
Fibrinogen
Ferritin
Troponin – Highly specific marker for myocardial infarction
Creatine kinase (CK-MB)
Brain natriuretic peptide (BNP) – For heart failure
Glucose and insulin levels – For assessing diabetes mellitus and insulin resistance

Additional tests include Lipoprotein(a), fasting insulin, HbA1c, and myoglobin.

Cardiovascular Risk Profile Table[edit]

Test	Normal/Low Risk	High Risk	Approximate Cost (USD)
Total Cholesterol	<200 mg/dL	>240 mg/dL	$50
LDL-C	<100 mg/dL	>160 mg/dL	$150*
HDL-C	>60 mg/dL	<40 mg/dL	$50
Triglycerides	<150 mg/dL	>200 mg/dL	$75
Blood Pressure	<120/80 mmHg	>140/90 mmHg	Variable
C-Reactive Protein	<1 mg/L	>3 mg/L	$20
Fibrinogen	<300 mg/dL	>460 mg/dL	$100
Homocysteine	<10 μmol/L	>14 μmol/L	$200
Fasting Insulin	<15 μIU/mL	>25 μIU/mL	$75
Lipoprotein(a)	<14 mg/dL	>19 mg/dL	$75
Coronary Calcium Score	<100	>300	$250–600

LDL-C is often calculated using the Friedewald formula due to cost.

Electrophysiology[edit]

Electrocardiogram (ECG or EKG)[edit]

An electrocardiogram records the heart’s electrical activity and is a cornerstone in diagnosing arrhythmias, myocardial infarction, electrolyte imbalance, and cardiac ischemia. A standard 12-lead ECG provides a comprehensive view of cardiac conduction in multiple planes.

Holter Monitor[edit]

A Holter monitor is a portable ECG device that continuously records for 24–48 hours. It is useful for detecting frequent but transient arrhythmias.

Event Monitor[edit]

An event monitor records heart rhythms for 1–2 weeks and is triggered by the patient when symptoms occur. It is suitable for detecting infrequent arrhythmias.

Cardiac Stress Testing[edit]

Cardiac stress testing assesses the heart’s response to exertion. It may be done using exercise or pharmacologic agents. Radionuclide imaging (e.g., with thallium or technetium) can be combined to identify areas of ischemia.

Target heart rate is commonly calculated as:

220 - age (in beats per minute)
Alternate formulas include:

Miller: 217 - (0.85 × Age)

High-frequency QRS complex analysis may improve sensitivity for detecting coronary artery disease during stress testing.

Electrophysiology Study (EPS)[edit]

An electrophysiology study is an invasive test using intracardiac catheters to map the heart’s conduction system. It is typically used to evaluate unexplained arrhythmias or assess suitability for radiofrequency ablation.

Medical Imaging[edit]

Cardiac Imaging Techniques[edit]

Echocardiography – Evaluates heart chambers, valves, and function.
Coronary catheterization – Invasive procedure to visualize coronary arteries.
Intravascular ultrasound (IVUS) – Visualizes vessel walls from inside arteries.
Coronary calcium scan – Detects coronary artery calcification.
Retinal vessel analysis – Evaluates microvascular changes reflecting cardiac health.

@@ Line 1: / Line 1: @@
-{{more citations needed|date=March 2013}}
+{{Short description|Methods for diagnosing heart conditions}}
-{{Infobox interventions
+'''Diagnostic tests in cardiology''' are used to identify various [[heart disease|cardiac conditions]] by evaluating heart structure, function, and electrical activity. These tests can be non-invasive or invasive and are used in both emergency and outpatient settings to aid in the diagnosis and management of [[cardiovascular disease]].
-| name        = Cardiology diagnostic tests and procedures
-| image       =
-| caption     =
-| ICD10       =
-| ICD9        = {{ICD9proc|89.4}}-{{ICD9proc|89.6}}
-| MeshID      = D006334
-| other_codes =
-}}
-The '''diagnostic tests in cardiology''' are methods of identifying [[heart]] conditions associated with healthy vs. unhealthy, [[pathology|pathologic]] heart function.
-==Bedside==
+== Bedside Assessment ==
-===History===
+=== Medical History ===
-Obtaining a [[medical history]] is always the first "test", part of understanding the likelihood of significant disease, as detectable within the current limitations of clinical medicine. Yet heart problems often produce no symptoms until very advanced, and many symptoms, such as palpitations and sensations of extra or missing heart beats correlate poorly with relative heart health ''vs'' disease. Hence, a history alone is rarely sufficient to diagnose a heart condition.
+Obtaining a thorough [[medical history]] is the first and most essential step in evaluating [[cardiac]] health. While some [[symptoms]] such as [[chest pain]], [[dyspnea]], or [[palpitations]] may point to significant [[heart disease]], other symptoms may be absent or misleading. Consequently, history alone is rarely sufficient to confirm or rule out a cardiac condition.
-===Auscultation===
+=== Auscultation ===
-''[[Auscultation]]'' employs a [[stethoscope]] to more easily hear various normal and abnormal sounds, such as normal heart beat sounds and the usual heart beat sound changes associated with breathing versus [[heart murmur]]s.
+[[Auscultation]] using a [[stethoscope]] allows clinicians to listen for normal and abnormal [[heart sounds]], such as [[murmurs]], [[gallops]], and [[rub|pericardial rubs]]. These may suggest underlying structural or functional abnormalities of the [[heart valves]] or chambers.
-==Laboratory==
+== Laboratory Investigations ==
-===Blood tests===
+=== Blood Tests ===
-A variety of ''[[blood test]]s'' are available for analyzing [[cholesterol]] transport behavior, [[High density lipoprotein|HDL]], [[Low density lipoprotein|LDL]], [[triglyceride]]s, [[lipoprotein little a]], [[homocysteine]], [[C-reactive protein]], blood sugar control: fasting, after eating or averages using glycosylated albumen or hemoglobin, [[myoglobin]], [[creatine kinase]], [[troponin]], [[brain-type natriuretic peptide]], etc. to assess the evolution of [[coronary artery disease]] and evidence of existing damage. A great many more [[physiology|physiologic]] markers related to [[atherosclerosis]] and heart function are used and being developed and evaluated in research.
+Various blood tests help in the evaluation of [[cardiovascular risk]] and myocardial injury:
+* [[Lipid profile]] – Total cholesterol, [[LDL]], [[HDL]], [[triglycerides]]
+* [[C-reactive protein]] – Marker of inflammation
+* [[Homocysteine]]
+* [[Fibrinogen]]
+* [[Ferritin]]
+* [[Troponin]] – Highly specific marker for myocardial infarction
+* [[Creatine kinase (CK-MB)]]
+* [[Brain natriuretic peptide (BNP)]] – For [[heart failure]]
+* [[Glucose]] and [[insulin]] levels – For assessing [[diabetes mellitus]] and insulin resistance
-{| class="wikitable" style="text-align:center"
+Additional tests include [[Lipoprotein(a)]], [[fasting insulin]], [[HbA1c]], and [[myoglobin]].
-|+ '''Cardiology diagnostic tests'''
-! Test Name !! Lower/normal risk !! High risk !! Cost $US<br>(approx)
+=== Cardiovascular Risk Profile Table ===
-|-
+{| class="wikitable"
-|-
+! Test !! Normal/Low Risk !! High Risk !! Approximate Cost (USD)
-|Total [[Cholesterol]] || <200&nbsp;mg/dL || >240&nbsp;mg/dL
 |-
-|[[Low density lipoprotein|LDL-C]]   ||    <100&nbsp;mg/dL  ||  >160&nbsp;mg/dL  ||  $150*
+| Total Cholesterol || <200 mg/dL || >240 mg/dL || $50
 |-
-|[[High density lipoprotein|HDL-C]]    ||   >60&nbsp;mg/dL   ||  <40&nbsp;mg/dL
+| LDL-C || <100 mg/dL || >160 mg/dL || $150*
 |-
-|[[Triglyceride]] || <150&nbsp;mg/dL || >200&nbsp;mg/dL
+| HDL-C || >60 mg/dL || <40 mg/dL || $50
 |-
-|[[Blood Pressure]] || <120/80 mmHg|| >140/90 mmHg
+| Triglycerides || <150 mg/dL || >200 mg/dL || $75
 |-
+| Blood Pressure || <120/80 mmHg || >140/90 mmHg || Variable
 |-
-|[[C-reactive protein]] || <1&nbsp;mg/L || >3&nbsp;mg/L || $20
+| C-Reactive Protein || <1 mg/L || >3 mg/L || $20
 |-
-|[[Fibrinogen]]  || <300&nbsp;mg/dL || >460&nbsp;mg/dL || $100
+| Fibrinogen || <300 mg/dL || >460 mg/dL || $100
 |-
-|[[Homocysteine]] || <10 μmol/L || >14 μmol/L || $200
+| Homocysteine || <10 μmol/L || >14 μmol/L || $200
 |-
-|[[Insulin|Fasting Insulin]] || <15 μIU/mL || >25 μIU/mL || $75
+| Fasting Insulin || <15 μIU/mL || >25 μIU/mL || $75
 |-
-|[[Ferritin]] || male 12–300&nbsp;ng/mL<br> female 12–150&nbsp;ng/mL || || $85
+| Lipoprotein(a) || <14 mg/dL || >19 mg/dL || $75
 |-
-|[[Lipoprotein]](a) - Lp(a)  || <14&nbsp;mg/dL ||  >19&nbsp;mg/dL ||  $75
+| Coronary Calcium Score || <100 || >300 || $250–600
-|-
-|[[Coronary calcium scan]] ||  <100  ||   >300 ||  $250–600
 |}
-(*) due to the high cost, LDL is usually calculated instead of being measured directly<br>
+*LDL-C is often calculated using the Friedewald formula due to cost.
-source: Beyond Cholesterol, Julius Torelli MD, 2005 {{ISBN|0-312-34863-0}}
-==Electrophysiology==
+== Electrophysiology ==
-===Electrocardiogram===
+=== Electrocardiogram (ECG or EKG) ===
-''[[Electrocardiography]]'' (ECG/EKG in German vernacular. Elektrokardiogram) monitors [[electricity|electrical]] activity of the heart, primarily as recorded from the skin surface. A 12 lead recording, recording the electrical activity in three planes, anterior, posterior, and lateral is the most commonly used form. The ECG allows observation of the heart electrical activity by visualizing waveform beat origin (typically from the sinoatrial or SA node) following down the bundle of HIS and ultimately stimulating the ventricles to contract forcing blood through the body. Much can be learned by observing the QRS morphology (named for the respective portions of the polarization/repolarization waveform of the wave, P,Q,R,S,T wave). Rhythm abnormalities can also be visualized as in slow heart rate [[bradycardia]], or fast heart rate [[tachycardia]].
+An [[electrocardiogram]] records the heart’s electrical activity and is a cornerstone in diagnosing [[arrhythmias]], [[myocardial infarction]], [[electrolyte imbalance]], and [[cardiac ischemia]]. A standard [[12-lead ECG]] provides a comprehensive view of cardiac conduction in multiple planes.
-===Holter monitor===
+=== Holter Monitor ===
-A ''[[Holter monitor]]'' records a continuous EKG rhythm pattern (rarely a full EKG) for 24&nbsp;hours or more. These monitors are used for suspected frequent rhythm abnormalities, especially ones the wearer may not recognize by symptoms. They are more expensive than event monitors.
+A [[Holter monitor]] is a portable ECG device that continuously records for 24–48 hours. It is useful for detecting frequent but transient arrhythmias.
-===Event monitor===
+=== Event Monitor ===
-An ''[[event monitor]]'' records short term EKG rhythm patterns, generally storing the last 2 to 5&nbsp;minutes, adding in new and discarding old data, for 1 to 2 weeks or more. There are several different types with different capabilities. When the wearer presses a button on the monitor, it quits discarding old and continues recording for a short additional period. The wearer then plays the recording, via a standard phone connection, to a center with compatible receiving and rhythm printing equipment, after which the monitor is ready to record again.  These monitors are used for suspected infrequent rhythm abnormalities, especially ones the wearer does recognize by symptoms.  They are less expensive than Holter monitors.
+An [[event monitor]] records heart rhythms for 1–2 weeks and is triggered by the patient when symptoms occur. It is suitable for detecting infrequent arrhythmias.
-===Cardiac stress testing===
+=== Cardiac Stress Testing ===
-''[[Cardiac stress testing]]'' is used to determine to assess cardiac function and to disclose evidence of exertion-related cardiac [[Hypoxia (medical)|hypoxia]]. [[Radionuclide test]]ing using [[thallium]] or [[technetium]] can be used to demonstrate areas of perfusion abnormalities. With a maximal stress test the level of exercise is increased until the person's heart rate will not increase any higher, despite increased exercise. A fairly accurate estimate of the target heart rate, based on extensive clinical research, can be estimated by the formula 220 beats per minute minus patient's age. This linear relation is accurate up to about age 30, after which it mildly underestimates typical maximum attainable heart rates achievable by healthy individuals. Other formulas exist, such as that by Miller (217 - (0.85 × Age)) and others. Achieving a high enough heart rate at the end of exercise is critical to improving the sensitivity of the test to detect high grade heart artery [[stenosis]]. [[HFQRS|High frequency analysis]] of the QRS complex may be useful for detection of coronary artery disease during an exercise stress test.<ref>{{cite journal |last1=Gerald |first1=F |last2=Philip |first2=A |last3=Kligfield |first3=P |display-authors=et al |title=Exercise Standards for Testing and Training A Scientific Statement From the American Heart Association |journal=American Heart Association |date=August 2013 |issue=128 |pages=873–934}}</ref>
+[[Cardiac stress testing]] assesses the heart’s response to exertion. It may be done using exercise or pharmacologic agents. [[Radionuclide imaging]] (e.g., with [[thallium]] or [[technetium]]) can be combined to identify areas of [[ischemia]].
-===Electrophysiology study===
+Target heart rate is commonly calculated as:
-The [[electrophysiology study]] or EP study is the end all of electrophysiological tests of the heart.  It involves a catheter with electrodes probing the endocardium, the inside of the heart, and testing the conduction pathways and electrical activity of individual areas of the heart.
+* '''220 - age''' (in beats per minute)
+* Alternate formulas include:
+''' Miller: 217 - (0.85 × Age)
-==Medical imaging==
+High-frequency [[QRS complex]] analysis may improve sensitivity for detecting [[coronary artery disease]] during stress testing.
-{{main|Cardiac imaging}}
-Cardiac imaging techniques include [[coronary catheterization]], [[echocardiogram]], [[intravascular ultrasound]], [[retinal vessel analysis]] and the [[coronary calcium scan]].
-== See also ==
+=== Electrophysiology Study (EPS) ===
-* [[Cardiology]]
+An [[electrophysiology study]] is an invasive test using intracardiac catheters to map the heart’s conduction system. It is typically used to evaluate unexplained arrhythmias or assess suitability for [[radiofrequency ablation]].
-* [[Reference ranges for common blood tests]]
-* [[Medical technologist]]
-==References==
+== Medical Imaging ==
-<references />
+=== Cardiac Imaging Techniques ===
+* [[Echocardiography]] – Evaluates heart chambers, valves, and function.
+* [[Coronary catheterization]] – Invasive procedure to visualize coronary arteries.
+* [[Intravascular ultrasound (IVUS)]] – Visualizes vessel walls from inside arteries.
+* [[Coronary calcium scan]] – Detects coronary artery [[calcification]].
+* [[Retinal vessel analysis]] – Evaluates microvascular changes reflecting cardiac health.
+== See Also ==
+* [[Cardiac imaging]]
+* [[Electrocardiography]]
+* [[Stress test]]
+* [[Cardiac catheterization]]
+* [[Arrhythmia]]
+* [[Heart failure]]
+* [[Coronary artery disease]]
+* [[Cardiac biomarkers]]
+[[Category:Cardiology]]
+[[Category:Medical tests]]
+[[Category:Cardiac electrophysiology]]
+[[Category:Heart diseases]]
 {{Cardiac procedures}}
 [[Category:Cardiac procedures]]
-{{No image}}