Cardiac Labs Flashcards
What is systole
Ventricular contraction
What is diastole
atrial contraction and ventricular relaxation
What causes the S1 sound
mitral valve closes
What causes the S2 sound
the aortic valve closes
What happens during Diastole
• LV pressure drops → mitral valve then opens →Opening Snap → rapid flow of blood to the LV wall→ S3 sound (nml in children and young adults, S3 gallop in older adults can be pathologic)→LA contracts → produces S4 (diseased wall → narrowing, CHF).
What causes the split of the S2 heart sound
The pulmonary valve closing slightly after the aortic valve
Cardiac output=
HRxSV
What 3 things determine stroke volume
Preload, Afterload & Muscle Contraction
What is preload
Volume that stretches the cardiac muscle prior to contraction
What is Afterload
Vascular resistance
What is Muscle Contractility
The ability for the cardiac muscle to contract when given a volume
What is Systolic Pressure
The maximum pressure during systole
What is Diastolic pressure
the lowest pressure during diastole
mean arterial pressure=
Diastolic + 1/3(Systolic –Diastolic)
What is a dicrotic notch
Back flow of blood from Aortic valve, creates a small pressure as the valve is closing
What does an A wave show in venous pulsation
atrial contraction
what does x descent show in venous pulsation
Starts with atrial relaxation and continues with RV contraction (which pulls the floor of the RA downwards).
• V wave = Tricuspid closure and rise in RA pressure.
what does V wave show in venous pulsation
Tricuspid closure and rise in RA pressure.
What does Y descent show in in venous pulsation
Opening of the Tricuspid and drop in the RA pressure
Normal Cardiovascular Vital Signs for
- BP
- Mean arterial pressure
- central venous pressure
- Pulmonary Artery pressure
- Heart Rate
- 60mmHg
- 8-12mmHg
- 6-12 mmHg
- 60-100
What are common signs and symptoms of a pathological heart
o Chest Pain/Discomfort Dyspnea, Paroxysmal nocturnal dyspnea oOrthopnea—difficulty breathing while supine oCyanosis oHyper/Hypotension oLightheadedness/Presyncope/Syncope o Peripheral edema, anasarca o Cardiac Arrthymias (Supraventricular, AV nodal, and Ventricular) o Palpitations o Pulmonary edema o EKG changes
what is pulsus paradoxus
A drop in Systolic pressure by >10 mmHg during inspiration due to increased pressure in the thoracic compartment.
Where is aortic stenosis best heard
aortic area during systole
Where is aortic regurgitation best heard
along the Left lateral border during diastole
Where is mitral stenosis best heard
apex during diastole
Where is mitral regurgitation best heard
apex during systole
what are the 4 guidelines by the NY heart association for approach to cardiac patient
Determine underlying etiology
Determine id an anatomic abnormality present
Detertemine if a physiologic disturbance is present
determine if a functional disability is present (is Pt able to perform strenuous tasks)
How to obtain cardiac diagnosis
obtain history Physical exam Lab tests Noninvasive diagnostic Test Invasive diagnostic Test
When does creatine kinase peak
•Peaks 4-8 hours post infarction and declines after 2-3 days. Peak is usually after 24 hours
What are the 3 Creatine kinase isoenzymes
MM (skeletal and cardiac), BB (brain and kidney) and MB –MC’ly checked (cardiac and skeletal
What is the ration of CK/MB that is indicative of MI
2.5 or greater of MB
What are the 3 types of troponin?
o Troponin C which binds calcium
o Troponin I which binds to actin and inhibits actin-myosin interactions
o Troponin T binds to tropomyosin thereby attaching the troponin complex to the thin filament.
When is Troponin released
•Released when a myocyte is damaged after about 3 hours and persist for 7 to 10 days (Trop I) and can last upwards of 10-14 days. (Trop T)
What causes an increase in BNP
Anything that increases pressure in the Atria
What is the value of BNP that is a high predictive value of CHF
> 400pg/dl
How does Echocardiography work
• Uses ultrasound technology to visualize the heart
What is 1st line Echocardiography used with
2D Trans-Thoracic Echocardiogram Shows: Cardiac chambers Valves Pericardium Great vessels Masses
When is a Trans-Esophageal Ecocardiogram used (TEE)
Used to better visualize mitral valve
What is doppler Echocardiography used for
o Valve Stenosis • Gradient • Valve area o Valve Regurgitation o Intracardiac pressures o Volumetric flow o Diastolic filling o Intracardiac shunts (right to left shunt) (“bubble” studies)
How are stress Echocardiography performed
Pharmacologic agents to induce stress in the heart
How does nuclear imaging work
• Injection of a radioactive isotope, which emits photons.
What is the problem with isotopes
that that it emits photons in all directions
What is Nuclear imaging used to assess
Ventricular functioning, myocardial perfusion (stress vs resting using exercise or pharmacologic stress i.e. adenosine or dipyridoamole or dobutamine)
How is a stress tests chosen?
determined upon the initial EKG, pts physical ability, and underlying diseases.
What types of stress testing are available
oStress Electrocardiography • Dukes Treadmill Score oStress Echocardiography • Decreased Ejection Fraction and decreased end diastolic volume or WMA/ oStress Nuclear Imaging • Imaging Defects oExercise Stress Testing • Bruce Protocol
What is MRI/CT imaging used for
evaluate complex anatomical abnormalities
What is CT good for evaluating
o Good at evaluation of pericardial calcification (constrictive pericarditis), cardiac masses, coronary calcifications (a marker of CAD)
What is CTA used to evaluate
evaluates intra-vessel abnormalities
What does cardiac angiography look for
looks for areas of narrowing in R/L Coronary Artery, L anterior descending, & circumflex.
When is cardiac angiography indicated
when cardiac disease needs conformation
when is cardiac angiography contraindicated
oInfants < 1 mo old, elderly > 85 yo
oFunctional Class IV 10x greater than I-II
oL main disease
oValvular disease
oEF < 30%
oRenal disease, DM, vascular disease, severe pulmonary disease
what are complication of Cardiac angiography
o CVA, MI, Arrhythmia, vessel damage (rupture/dissection), heart damage (rupture), renal failure or allergic reactions from contrast dye
When can stents be used
can only be put in proximal area, if it’s too distal, bypass is needed to remove block
What is the problem with using a pulmonary artery catheter
difficult to interpret and rarely used
What are the problems with Pulmonary Artery Catheter
inappropriately interpreting data
Increased intrathoracic pressure can give falsely elevated PAOP by increasing intracardiac pressure
Left ventricle compliance is an important factor and can be altered
Myocardial stiffness
Pulmonary Artery Occlusion Pressure (NOT FOR DETERMINING INTRAVASCULAR VOLUME)
