sudden cardiac-death

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  • Sudden Cardiac DeathDR ABDULPGY3MEM

  • DefinitionThe natural death from cardiac causes, heralded by abrupt loss of consciousness within 1 hour of the onset of an acute change in cardiovascular status.

    is an unexpecteddeathdue tocardiaccauses that occurs in a short time period (generally within 1 hour of symptom onset) in a person with known or unknowncardiacdisease.*

  • Epidemiology 300,000 cases per year1-2/1000Bimodal distribution

    *Highest risk between birth and 6months or 45yrs to 75yrs

  • CausesLong QT SyndromeBrugada SyndromeHypertrophic Cardiomyopathy Arrhythmogenic Right Ventricular Dysplasia Commotio Cordis Coronary Anomaly

    K chanellopathyNa chanellopathyMuscle mass thicknessDeposition of muscle with fatSudden force over precordium leading to vt*

  • Long QT SyndromeAutosomal Dominate- Romano-WardAutosomal Recessive- Jervell and Lange-NielsenAcquired1/10,000

    *Aprox 1 in 2500 to 1 in 10,000 w/ genetic LGTs. JLN-occurrs in around 3-3.5% of kids w/ congenital neuronal deafness-has a more malignant course

    As much as 15% of pt w/ acguired L QT have and underlying mutationACQUIRED:A:DRUGS:1.AMPHETAMINE:COCAINE,EPHEDRINE,2.ANTICHOLERNERGICS:ATROPINE,AMITRIPTYLINE,DIPHENIREHYDRAMINE,ALPRAX,CITRIZINE,3.MACROLIDS:AZITHRO,ERYTHRO,CLARITHROMYCIN B>ELECTROLYTEDISTURBANCE C.HYPOTHERMIAAutosomal dominat:1 copy of gene sufficient to cause disease,autosomal recessive :2copy of genes necessary to disese develope

  • *Phase 0- rapid depolarization phase- fast sodium channels open-rapid influx of positively charges ion. Phase 1-closure of fast Na channels O and 1=R and S wavePhase 2-platue phase-balance between inward mvt of Cal and outward mvt of K,very slow k effulux ..thus channels remain open for prolonged time ..qt prolongationPhase 3-repolarization phase outward flow of K-T wavePhase 4-resting membrane potential

    blocking/slowing Na influx or K eflux causes a prolongation of the qt interval (Duration of activation and recovery of ventricular myocardium), if prolongation is long enough can get a second excitation phase from myocardium (early after-depolarization) leads to loose of synchronization and arrhythemia--ankyirin-thought to effect Na channels

  • *FIGure---R-W: Romano-Ward syndrome; J-L-N: Jervell and Lange-Nielsen syndrome with deafness; NR: not reported; HPP: hypokalemia periodic paralysis.* KCNE1 is also referred to as minK; KCNE2 is also referred to as MiRP1 (minK related protein 1). The KvLQT1 gene encodes the alpha-subunit protein of the IKs channel, with the KCNE1 gene encoding the beta- subunit protein of this same channel. The alpha- and beta-subunit proteins combine together to form a cardiac potassium channel expressing the IKs (slowly activating component of delayed rectifier potassium current); Ikr is the rapidly activating component of delayed rectifier potassium current.Amended with permission from Schwartz, PJ, Priori, SG, Napolitano C. Long QT syndrome in Zipes, DP, Jalife, J (Eds.) Cardiac Electrophysiology: From Cell to Bedside. Orlando, Fla: WB Saunders. 1999.

    LQT1-account for 40-55% of cases

    LQT2- 35-45%

    LQT3-8-10%

    Others 2-5% each

  • PresentationPalpitations, Presyncope, Syncope, Seizures, or Cardiac arrestAsymptomatic prolonged QTcReferred by family membersHas a predilection for younger patient

    *Pressentation can depend on genetics LGT1-exercise-related events, LQT2-auditory-allarm clocks or phones, LQT3-events at rest or sleep

    Seems to afeect younger pt, syncope and SCD unusual in pt older then 40

  • 1 small box =.04sec,1 large box =.2sec,5 large box =1sec*

  • *LGT1-broad T waveLGT2-low-amplitude-bifid T waveLQT3-long isoelectric segment followed by a narrow tall Twave

  • http://www.torsades.org/

    *10-15% of pts w/ acquired LGT have underlying genetics

  • Diagnosis: Schwartz score

    *-provacation with epinephrine for LGT1-give epi and qt increaseTo make a definitive diagnosis score of greater than 4 is needed

  • TherapyNEJM 2008; 358:169-175

    *Long acting BB

  • Brugada SyndromeAutosomal dominate defect in cardiac Na channels- variable expression0.4% US populationMale predominanceAverage age of Dx=41

    *Incidence increases in asian populations, first described in asiansAprox 18% of pt w/ syndrome have gene, variable penetranceRarely dx in children

  • Texas Heart Inst J 2007;34:67-75

    In a normal condition :there is almost simultaneous excitation of endo & epicardium due to N functioning NA channels but in case of brugada action potential is delayed due to slow opening or block in NA channels .leading to a lag b/w endocardium & epicardium aka phase 2 reentry,PHASE 2 WILL BE SHORTNEDEpicardium has shortest AP{high conc. Of ions},endocardium has longest AP

    Loss-of-function mutations in this gene lead to a loss of the action potential dome of some epicardial areas of the right ventricle. This results in transmural andepicardialdispersion ofrepolarizatio*

  • PresentationFunny looking ECGSCD/Syncope TriggersFeverSleepGlucose/insulinCocaine/ETOHElectrolytes

    *SCD-initial pressentation in aprox 30%, -Three distinct types of ST segment elevation have been described. In type 1, the ST segment gradually descends to an inverted T wave. In type 2, the T wave is positive or biphasic, and the terminal portion of the ST segment is elevated 1 mm. In type 3, the T wave is positive, and the terminal portion of the ST segment is elevated

  • Unmasking AgentsNa channel blockers-ajmalineCalcium Channel blockersBeta blockersNitratesTricyclicsSSRI

  • Prognosis & TREATMENTSCD or VF/VTSyncope

    *Pts w/ SCD / VF have aprox 25% chance of a second event w/in 2 yrs Pts pressenting w/ syncope have a six fold increase in SCD above asymptomatic ptPt w/ spontaneous type I pattern were three times more likely up to 15% in 2 yrs follow up

    TREATMENT IS AICD PLACEMENT OR MEDICALLY BY QUINIDINE CLASS 1 ANTIARYTHIMIC {BLOCKE FAST NA CHANNELS}

  • Hypertrophic Cardiomyopathy defect in the myocardial contractile proteins

    HCM is a familial disease

    hallmark : myocardial hypertrophy that is inappropriate, often asymmetrical, and occurs in the absence of an obvious inciting hypertrophy stimulus.

    *Prt affected: cardiac troponin T, cardiac troponin I, myosin regulatory chain, myosin essential light chain, cardiac myosin binding protein-C, alpha and beta-cardiac myosin heavy chain, cardiac alpha actin, alpha tropomyosin, and titin. -more common in men and AA

  • HCM involves changes in connective tissue elements as well as sarcomere proteins l

    disorganized myocyte architecture, including with bizarre-shaped nuclei, widespread interstitial fibrosis . *

  • *387 high school age/college age in minnasoata

  • PresentationSCDDOESyncopeHeart failureChest PainPalpitationAsymptomatic

    *No good correlation bettwen degree of obstruction and severity of symptoms-DOE most common syptom >90 of symptomatic pts, 2/2 to diastolic dysfunction, MR, empaired LV emptying-syncope occurs in 15-25% of pt w/ at least one episode 2/2 to inadequate cardiac out put or ischemia or ventricular barofeflex w/ inappropriate vasodialtionsmall chamber size is risk factor

  • Physical ExamSystolic Crescendo-decrescendo murmur LLSB/apexDecreases w/ squatting, hand dripIncrease w/ standingBifid pulsesEKG-LVH

    *

  • DiagnosisECHO

    *LV wall thickness >=15, with out other causes HTN, AS, differientiate from athlete heart

  • TreatmentPharmocologicVerapamilBeta blockers

    ICDClass I- h/o sustained VT/VFOne or more major risk factor Ablation/Surgery

    *--Verapamil/bb slow HR and prolong diastoling allowing more filling, decrease 02 demand--Beatblokcer--Disopyramide-antiarrythmic and negative iontrop****use w/ caution vasodilator-nefidipine NTG, ACE, decrease PVR inc gradient-diuretics decrease preload andless LV fillling smaller change greater out flow obstruction===ICD need to be on apropriate medical management and have life exspectancy of a year+++ETOH septal ablation or surgical myomectomies in pt w/ severe obstruction >50mmhg/ refractory symptoms

  • Arrhythmogenic Right Ventricular DysplasiaDefective DesmosomeFibrofatty replacement of the RV myocardium1:1000Autosomal dominant -mcf

    *fibrofatty replacement of the RV myocardium initially produces typical regional wall motion abnormalities that later become global, producing RV dilation. The tissue replacement can also involve area of the left ventricle (LV) with relative sparing of the septum -dispite the name in can occur in the LV as well, infact these proteens a poorer prognosis w/ higher incidence of arryhtmia and CHF--an autosomal dominant form, which is most common, and an autosomal recessive form called Naxos disease, in which ARVD is part of a syndrome including hyperkeratosis of the palms and soles and woolly hair.

    --)

  • *. Panel A:Four chamber view cut of the heart specimen showing the trans mural fatty replacement of the right ventricular free wall and the translucent infundibulum. Panel B: Panoramic histologic view of the same heart confirming that the replacement of the myocardium by fat is largely confined to the right ventricle (arrow) and substantially spares the interventricular septum as well as the left ventricular free wall (trichrome Heidenhain x 3).

  • PresentationAsymptomaticPalpitation, syncope, atypical chest pain, dyspneaArrhythmiasSCDExercise associated

    *Palpitations 67 percent Syncope 32 percent Atypical chest pain 27 percent Dyspnea 11 percent Signs of Right heart failure are rare, clinical pressentation is usualy arrthymia (50%)/SCD or incidental findin

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