Presentation is loading. Please wait.

Presentation is loading. Please wait.

Sudden Cardiac Death in Structurally Normal Heart Brian D. Le, MD Presbyterian Hospital CIVA.

Similar presentations


Presentation on theme: "Sudden Cardiac Death in Structurally Normal Heart Brian D. Le, MD Presbyterian Hospital CIVA."— Presentation transcript:

1 Sudden Cardiac Death in Structurally Normal Heart Brian D. Le, MD Presbyterian Hospital CIVA

2 Presentation –HPI-35 yo WM s PMH presents with exertional syncope h/o PAF since 18 yrs of age h/o PAF since 18 yrs of age Holter- monomorphic isolated PVC’s Holter- monomorphic isolated PVC’s Echo- structurally normal heart Echo- structurally normal heart –Meds- no OTC or herbal –Social- occ. Etoh, no IVDA –Family History Sister (31) - dizziness and palpitations Sister (31) - dizziness and palpitations Sister’s son (6) - cardiac arrest at 8 mo old after a loud noise with successful DCCV Sister’s son (6) - cardiac arrest at 8 mo old after a loud noise with successful DCCV Gaita et al. Circulation. 2003; 108

3 A- 35 yo WM c syncope A- 35 yo WM c syncope B- 31 yo sister, dizziness and palpitations B- 31 yo sister, dizziness and palpitations C- 6 yo son, SCD C- 6 yo son, SCD

4 Sudden Cardiac Death “Unexpected death from cardiac cause within a short time (~1 hour of sx) in a person without prior conditions that would appear fatal.” “Unexpected death from cardiac cause within a short time (~1 hour of sx) in a person without prior conditions that would appear fatal.” 300-400,000 deaths annually (U.S.). 300-400,000 deaths annually (U.S.). VT/VF account for 80%. VT/VF account for 80%. 20% have structurally normal hearts. 20% have structurally normal hearts. Wever E, et al. JACC. Vol 43, 2004.

5 Sudden Cardiac Death Normal hearts, < 40 years old Normal hearts, < 40 years old < 30% successful resuscitation reaching hospital < 30% successful resuscitation reaching hospital Risk of life-threatening events in cardiac arrest survivors is 25-40% at two years Risk of life-threatening events in cardiac arrest survivors is 25-40% at two years Wever E, et al. JACC. Vol 43, 2004.

6 Primary Electrophysiologic Abnormalities WPW: anterograde BPT ERP <250ms. WPW: anterograde BPT ERP <250ms. Brugada: RBBB w/ST elevation V1-V3 Brugada: RBBB w/ST elevation V1-V3 Catecholamine Polymorphic VT: hRyR2. Catecholamine Polymorphic VT: hRyR2. Long QT: QTc (>440ms), TdP w/long coupled PVC (600-800ms). Long QT: QTc (>440ms), TdP w/long coupled PVC (600-800ms). Short-coupled TdP: normal QTc, PVC w/short coupling (200-300ms). Short-coupled TdP: normal QTc, PVC w/short coupling (200-300ms). Short QT syndrome Short QT syndrome Idiopathic VF Idiopathic VF

7 Brugada’s

8 Catecholaminergic Polymorphic VT

9 Idiopathic VF

10 A- 35 yo WM c syncope A- 35 yo WM c syncope B- 31 yo sister, dizziness and palpitations B- 31 yo sister, dizziness and palpitations C- 6 yo son, SCD C- 6 yo son, SCD

11 Evaluation Physical Exam Physical Exam Serial ECG’s Serial ECG’s Holter Holter Heart rate variability Heart rate variability QT dispersion QT dispersion Signal-averaged ECG Signal-averaged ECG Echocardiogram Echocardiogram Cardiac MRI Cardiac MRI Electrophysiological Study Electrophysiological Study

12 QT Interval Represents ventricular repolarization. Represents ventricular repolarization. Normal QTc upper limit: 440ms. Normal QTc upper limit: 440ms. Bazett’s formula: QTc = QT/ RR Bazett’s formula: QTc = QT/ RR Rautaharju formula (14,379 pts): Rautaharju formula (14,379 pts): –QTp (ms)= 656/ (1+HR/100) –QT/QTp x 100% = % QTpredicted. –88% of QTp = 2 SD below mean –Lower limit of nl QT int. = 88% of QTp

13 QT Interval and SCD Algra et al. Br.Ht.J. 1993;70:43-8. Algra et al. Br.Ht.J. 1993;70:43-8. –Nested cohort 6693 consecutive pts w/24 ECG. –F/U 2.5 years in 99.5% of pts. –End point: QTc correlation w/SCD (104 pts). –Results: QTc >= 440ms  2.3 RR of SCD. QTc >= 440ms  2.3 RR of SCD. QTc < 400ms  2.4 RR of SCD. QTc < 400ms  2.4 RR of SCD.

14 Familial Short QT Gussak et al. Cardiology 2000;94:99- 102. Gussak et al. Cardiology 2000;94:99- 102. –3 members of one family; age 17-51 yo. –Palpitations, sx PAF, syncope  SCD –All w/ structurally normal hearts. –All w/ S-QT (260-280ms); QT interval <80% predicted by Rautaharju method.

15 Factors That Shorten QT Increase in heart rate Increase in heart rate Hyperthermia Hyperthermia Hypercalcemia Hypercalcemia Hyperkalemia Hyperkalemia Acidosis Acidosis Changes in autonomic tone Changes in autonomic tone

16 Genetic Basis of Short QT Brugada, Antzelevitch, et al. Circ. 2004;109:30-5. Brugada, Antzelevitch, et al. Circ. 2004;109:30-5. –Different missense mutations in same residue codon 588 of KCNH2 (HERG [IKr]). –Mutations only seen in sQT, and not in normal relatives. –Patch clamp models

17 Heterogeneity of Short QT Genetic Studies- KCNQ1 gene mutation G for C, subs. valine for leucine (IKs) Genetic Studies- KCNQ1 gene mutation G for C, subs. valine for leucine (IKs) Mutations negative in 200 unrelated controlled individuals Mutations negative in 200 unrelated controlled individuals Loss of function leads  LQT1 Loss of function leads  LQT1 Bellocq et al. Circulation. 109; 2004

18 KCNJ2, encoding for inwardly rectifying K channel Kir2.1 KCNJ2, encoding for inwardly rectifying K channel Kir2.1 Rapid repolarization Rapid repolarization SQT3 SQT3 Loss of function results in LQT7 (Anderson’s disease) Loss of function results in LQT7 (Anderson’s disease) Priori et al. Circ. Res. 2005; 96

19 Ion Channel Mutations Loss of Function Loss of Function –SCN5A  Brugada –IKs  LQT1 –IKr  LQT2 Gain of Function Gain of Function –SCN5A  LQT3 –IKs  Fam. A. Fib., Short QT –IKr  Short QT 4 012 3 Na Ca > Na IKr & IKs

20 Short QT Syndrome Rx Gaita et al. JACC. 2004;43:1494-9. Gaita et al. JACC. 2004;43:1494-9. –6 pts. from 2 different families. –Drugs: Flecainide (IV or oral), Sotalol, Ibutilide, and Hydroquinidine.

21 Short QT Rx Results Flecainide: slight inc. QT due to QRS prolongation. Flecainide: slight inc. QT due to QRS prolongation. Ibutilide & Sotalol: no change in QT Ibutilide & Sotalol: no change in QT Hydroquinidine: Hydroquinidine: –5/6 pts- QTc normalized (290  405ms) –EPS 5/5 pts- inc. VERP, no VF/VT –F/U 11 mos- 4/6 on hydroquinidine w/o sx or arrhythmias detected by ICD.

22 Ventricular ERP

23

24 Quinidine VW Class: Ia (sodium channel blocker) VW Class: Ia (sodium channel blocker) Blocks: INa, IKr, IKs, Ito, L-type Ca2+, IK1(in.rect.), & IKATP  QT increase. Blocks: INa, IKr, IKs, Ito, L-type Ca2+, IK1(in.rect.), & IKATP  QT increase. Adverse effects: diarrhea, SLE, thrombocytopenia, hepatitis, cinchonism (tinnitus/HA), TdP, many drug interactions 2/2 block of CYP2D6. Adverse effects: diarrhea, SLE, thrombocytopenia, hepatitis, cinchonism (tinnitus/HA), TdP, many drug interactions 2/2 block of CYP2D6.

25 ICD First line therapy First line therapy Risk of inappropriate shock delivery- Tw oversensing ( Schimpf et al. JCE. 14: Dec 2003 ) Risk of inappropriate shock delivery- Tw oversensing ( Schimpf et al. JCE. 14: Dec 2003 )

26 - Ventricular ERP- <150ms- induction of VF - Atrial ERP- 120ms Circulation. 2003; 108

27 Family Tree 39 yo Circulation. 2003; 108 8 mo 49 yo 39 yo

28 Schimpf, et al. Heart Rhythm. 2004;2

29 Summary Short QT Syndrome Significantly short QTc <= 300ms. Significantly short QTc <= 300ms. Tall & peaked T-waves. Tall & peaked T-waves. Clinical: palpitations, syncope, SCD. Clinical: palpitations, syncope, SCD. Significant FHX of SCD. Significant FHX of SCD. Atrial and ventricular arrhythmias. Atrial and ventricular arrhythmias. Structurally normal hearts. Structurally normal hearts. Treatment: ICD and/or Quinidine. Treatment: ICD and/or Quinidine.


Download ppt "Sudden Cardiac Death in Structurally Normal Heart Brian D. Le, MD Presbyterian Hospital CIVA."

Similar presentations


Ads by Google