View source for Medicine:Cardiology diagnostic tests and procedures

{{Infobox interventions
| name        = Cardiology diagnostic tests and procedures
| image       =
| caption     =
| ICD10       =
| ICD9        = {{ICD9proc|89.4}}-{{ICD9proc|89.6}}
| MeshID      = D006334
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The '''diagnostic tests in cardiology''' are methods of identifying [[Biology:Heart|heart]] conditions associated with healthy vs. unhealthy, [[Biology:Pathology|pathologic]] heart function.

==Bedside==

===History===
Obtaining a [[Medicine:Medical history|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.

===Auscultation===
''Auscultation'' employs a [[Engineering:Stethoscope|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 [[Physics:Heart murmur|heart murmur]]s.

==Laboratory==

===Blood tests===
A variety of ''[[Medicine:Blood test|blood test]]s'' are available for analyzing [[Chemistry:Cholesterol|cholesterol]] transport behavior, HDL, LDL, [[Chemistry:Triglyceride|triglyceride]]s, lipoprotein little a, [[Chemistry:Homocysteine|homocysteine]], [[Chemistry:C-reactive protein|C-reactive protein]], blood sugar control: fasting, after eating or averages using glycated albumen or hemoglobin, [[Biology:Myoglobin|myoglobin]], [[Biology:Creatine kinase|creatine kinase]], [[Biology:Troponin|troponin]], brain-type natriuretic peptide, etc. to assess the evolution of [[Medicine:Coronary artery disease|coronary artery disease]] and evidence of existing damage. A great many more [[Biology:Physiology|physiologic]] markers related to [[Medicine:Atherosclerosis|atherosclerosis]] and heart function are used and being developed and evaluated in research.

{| class="wikitable" style="text-align:center"
|+ '''Cardiology diagnostic tests'''
! Test Name !! Lower/normal risk !! High risk !! Cost $US<br>(approx)
|-
|-
|Total [[Chemistry:Cholesterol|Cholesterol]] || <200&nbsp;mg/dL || >240&nbsp;mg/dL
|-
|LDL-C   ||    <100&nbsp;mg/dL  ||  >160&nbsp;mg/dL  ||  $150*
|-
|HDL-C    ||   >60&nbsp;mg/dL   ||  <40&nbsp;mg/dL
|-
|[[Chemistry:Triglyceride|Triglyceride]] || <150&nbsp;mg/dL || >200&nbsp;mg/dL
|-
|Blood Pressure || <120/80 mmHg|| >140/90 mmHg
|-
|-
|[[Chemistry:C-reactive protein|C-reactive protein]] || <1&nbsp;mg/L || >3&nbsp;mg/L || $20
|-
|[[Biology:Fibrinogen|Fibrinogen]]  || <300&nbsp;mg/dL || >460&nbsp;mg/dL || $100
|-
|[[Chemistry:Homocysteine|Homocysteine]] || <10 μmol/L || >14 μmol/L || $200
|-
|[[Biology:Insulin|Fasting Insulin]] || <15 μIU/mL || >25 μIU/mL || $75
|-
|[[Biology:Ferritin|Ferritin]] || male 12–300&nbsp;ng/mL<br> female 12–150&nbsp;ng/mL || || $85
|-
|[[Biology:Lipoprotein|Lipoprotein]](a) - Lp(a)  || <14&nbsp;mg/dL ||  >19&nbsp;mg/dL ||  $75
|-
|Coronary calcium scan ||  <100  ||   >300 ||  $250–600
|}
(*) due to the high cost, LDL is usually calculated instead of being measured directly<br>
source: Beyond Cholesterol, Julius Torelli MD, 2005 {{ISBN|0-312-34863-0}}

==Electrophysiology==

===Electrocardiogram===
''[[Biology:Electrocardiography|Electrocardiography]]'' (ECG/EKG in German vernacular. Elektrokardiogram) monitors [[Physics: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 [[Medicine:Bradycardia|bradycardia]], or fast heart rate [[Medicine:Tachycardia|tachycardia]].

===Holter monitor===
A ''[[Engineering:Holter monitor|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.

===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.

===Cardiac stress testing===
''Cardiac stress testing'' is used to determine to assess cardiac function and to disclose evidence of exertion-related cardiac [[Medicine:Hypoxia (medical)|hypoxia]]. Radionuclide testing using [[Chemistry:Thallium|thallium]] or [[Chemistry:Technetium|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 [[Medicine:Stenosis|stenosis]]. 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>

===Electrophysiology study===
The [[Biology:Electrophysiology study|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.

==Medical imaging==
{{main|Medicine:Cardiac imaging}}
Cardiac imaging techniques include [[Medicine:Coronary catheterization|coronary catheterization]], echocardiogram, [[Medicine:Intravascular ultrasound|intravascular ultrasound]], [[Medicine:Retinal vessel analysis|retinal vessel analysis]] and the coronary calcium scan.

== See also ==
* [[Medicine:Cardiology|Cardiology]]
* Reference ranges for common blood tests
* Medical technologist

==References==
<references />

{{Cardiac procedures}}

[[Category:Cardiac procedures]]

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