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9 Cards in this Set
- Front
- Back
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Deefinition of SVT?
Is it always Narrow complex? Is it always regular? |
Generally any tachyarrhythmia that requires atrial and/or atrioventricular (AV) nodal tissue for its initiation and maintenance
WIDE Aberrant conduction during SVT results in a wide-complex tachycardia. IRREGULAR atrial fibrillation (AF) and multifocal atrial tachycardia (MAT). |
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Atrial tachycarrhythmias
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Sinus tachycardia
-physiologic response Inappropriate sinus tachycardia -ST in the absence of physiological stressors -(elevated resting and exaggerated response to exercise) -usually young women without structural heart dz -mechanism may be hypersensitivty of SN or SN abnormality SNRT (frequently confused with IST) -reentry circuit in or near the SN -abrupt onset/offset -HR 100-150 -can have normal p wave ätrial tachycardia - rare -originates in the atrial myocardium. -DUe to automaticity, triggered activity, or reentry -HR 120-250 -p wave morphology different from sinus (depends on site) -because does not involve AV node, AV blockers (adenosine, verapamil) don't work. MUltifocal atrial tachycardia (uncommon) -arises from atrial tissue, 3 or more pwave morphologys and HRs -usually elderly pts with pulmonary dx -treatment = correct underlying (+/- Mg, verapail) FLutter -arises above the av node -usually reentrant -can progress to AF Fibrillation -chaotic depolarisation |
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AV tachycardias
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AV nodal reentrant tachycardia
-most common caue of pSVT -HR 120-250 -requires a slow and fast pathway in node - the P wave is usually located at the terminal portion of the QRS complex AV reentrant tachycardia -second most common form of pSVT -Accessory pathways are errant strands of myocardium that bridge the mitral or tricuspid valves & connect the atria and the ventricles -accessory pathways can conduct up down or both Junctional ectopic tachycardia and nonparoxysmal junctional tachycardia -rare, dont care |
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Pericarditis Mx
Signs on exam? HIstory? Causes |
O2 telemetry
-r/o life threatening causes of chest pain -NSAIDS +/- ABx -echo, bloods CXR -?tamponade - pericardiocentesis -?cardiology Signs -tachypnoea -tachycardia -fever -pericardial rub -pericardial Hx -chest pain worse on inspuiration and movement, -Better with sitting forward, worse with lying down -radiates to trapezius ridge ?? neck Causes -viral -bacterial -radiation -uraemia -malignancy -vasculitis -autoimmune -tb |
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TIMI risk score
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What is it?
used to categorize the risk of death and ischemic events in patients experiencing unstable angina or a non-ST elevation myocardial infarction. It is used as a basis for therapeutic decision making 1 point for each: age >65 aspirin use in the last 7 days 2 angina episodes last 24hrs ST changes 0.5mm on admission ecg elevated enzymes known CAD >50% 3 RF for CAD Score Interpretation: % risk at 14 days of: all-cause mortality, new or recurrent MI, or severe recurrent ischemia requiring urgent revascularization. Score of 0-1 = 4.7% risk Score of 2 = 8.3% risk Score of 3 = 13.2% risk Score of 4 = 19.9% risk Score of 5 = 26.2% risk Score of 6-7 = at least 40.9% risk Mnemonic AMERICA: Age > 65 Markers (increased serum cardiac markers) EKG (ST depression) Risk factors (3 or more CAD risk factors: patient age, family history, hypercholesterolemia, hypertension, smoking, diabetes, obesity, sedentary lifestyle, metabolic syndrome) Ischemia (2 or more anginal events over past 24 hours) CAD (prior coronary stenosis of 50% or more) Aspirin use within past 7 days |
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JVP assessment
what is abnormal How do you differentiate from carotid artery |
measured at 45 degrees
Normal is less than 3cm above sternal angle(junction of the manubrium and the body of the sternum) = (5cm above RA) TIP use pen light to visualise, from the side Differentiating from artery: -multiphasic (2 beats for each cardiac) -non-palpable -occludable (JVP will stop) -varies with head tilt, respiration, ? liver pressure |
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calcium channel blockers
-MOA -classes |
block volatage gated calcium channels -cardiac and vascular
Classes Dihydropyridine & Non-Dihydropyridine Dihydropyridine -dipines Non-dihydropyridine -verapamil = selective for myocardium, -often used for angina -reduced myocardial o2 demand and coronary vasospasm -minimal vasodilatory effects hence less reflex tachycardia INTERMEDIATE Diltiazem |
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digoxin
MOA Indications AE |
MOA
inhibits Na/K ATPase==> increased intracellular Na, ==> intracellular ca (Na/Ca exchange) ==> lengthens phase 4 & 0==> slows HR (Ca also increases contractility) ?increased vagal stimulation INDICATIONS -AF -CCF AE Note: more likely in hypokalaemia as Digoxin competes with K for binding site -anorexia, n&v&d -blurred vision & yellowgreen halos -confusion/drowsiness -atrial tachycardia with AV block ECG changes - PR prolongation, bigeminy |
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nervous innervation of the heart?
intrinsic rates? |
SYMPATHETIC
-T2-T4 ==> Middle cervical, cervico-thoracic and 1st 4 throacic ganglion of sympathetic chain ==>cardiac plexus ==> SA node ==> cardiac muscle PARASYMPATHETIC vagus nerve ==> sa node(also decr excitability at AV node) remember can go on pumping without any direct stimulus INTRINSIC RATES SA - 60-100 AV 40-60 bundle of HIS 30-40 purkinje fibres 15-30 |
