Ambulatory Monitors, Pacers, and Defibrillators

Transcription

1 Ambulatory Monitors, Pacers, and Defibrillators Vermont Cardiac Network 2018 Mark L. Greenberg MD Clinical Associate Professor of Medicine Geisel School of Medicine, Dartmouth * September 26, 2018 Arrhythmia (dysrhythmia) Diagnosis History - Palpitations, aptato s,chest discomfort, o lightheadedness/dizziness/near-syncope, syncope, dyspnea, weakness/fatigue/exercise intolerance, anxiety, urinary frequency (post tachycardia diuresis). Palpitations--most common symptom in tachyarrhythmias An awareness of irregular or rapid heart action; distinguish ectopic beats from sustained palpitations from increased cardiac awareness Dizziness--very common symptom in clinical practice Distinguish cardiovascular etiology (near syncope) from neurologic etiology (vertigo, poor balance)

2 Diagnosis: ECG (12 lead) Short PR / WPW suggests that reciprocating tachycardia may be a likely mechanism Sinus bradycardia structural vs. functional (vagallymediated) sinus node dysfunction Prolonged PR /QRS suggest bradycardia related mechanisms for symptoms Long PR AV node disease; wide QRS disease below the AV node Pathologic Q waves prior myocardial infarction, a risk factor for reentrant VT Long QT / Short QT, Brugada syndrome, ARVC etc. Diagnosis: ECG Braunwald Heart Disease

3 Diagnosis: Ambulatory monitors Holter monitor hours Using a tape /digital recorder 3-5 surface leads recorded continuously Useful for frequent symptoms (at least daily or every other day) Can provide accurate information about rate control in persistent AFib Documentation of asymptomatic arrhythmias Onset and termination of arrhythmia Diagnosis: Ambulatory monitors Event Monitor 30 days 30 seconds of recording Patient activated Useful for infrequent symptoms Loop Recorder Using digital recorder with a loop buffer Programmable--seconds to minutes of single channel recording Useful for infrequent symptoms Patient vs auto-activation Can record onset and termination of arrhythmia

4 Smartphone Personal device, portable Available indefinitely Short recordings (seconds to minutes) Single lead Can be ed to personal health care provider or uploaded to website for interpretation (for a fee) Kardia, AliveCor.com Diagnosis: Ambulatory monitors Zio Patch 14 day battery Full disclosure Patient triggered events vs. auto- activation

5 Diagnosis: Ambulatory monitors Implantable Loop Recorder 2-3 year battery Small device with integrated leads Simple surgical implantation Auto and patient activated For infrequent episodes, elderly Can quantify AFib burden

6 Treatment of Bradyarrhythmias Remove offending drug or treat underlying condition e.g. Lyme disease Medications Stimulants: catecholamines, theophylline Vagolytics: hyoscyamine, propantheline, glycopyrrolate Pacemaker Indications for Pacing-- Abbreviated Symptomatic Bradycardia Regardless of mechanism Unreliable escape rhythm Infranodal conduction disease (e.g. Mobitz 2 second degree AV block, unstable trifascicular block)

7 Indications for Pacing--Expanded Symptomatic sinus node dysfunction/tachybrady d syndrome Symptomatic AV block/asymptomatic infranodal block Selected patients with syncope: bifascicular/trifascicular block, vasovagal syncope, carotid sinus hypersensitivity Prophylactic e.g. transient AV block in setting of anterior MI and BBB, myotonic dystrophy

8 5086MRI Lead Performance & Reliability 5076 Lead: >3.2 million sold, survivability 10 years* Materials identical to 5076** 5086MRI clinical implant experience starting February 2007 Lead Tip Connector Lead Body Over 72,000 leads implanted in USA (October 2012) *Medtronic data on file August 2014 **Exception of MRI Marker band and electrode coating Pacemaker components combine with body tissue to form a complete circuit Pulse generator: power source or battery Leads or wires Cathode (negative electrode) Anode (positive electrode) IPG Lead Body tissue Anode Cathode

9 Dual Chamber Pacemaker

10 VVI, AAI, DDD Device-speak VOO, AAO, DOO VVIR, AAIR, DDDR Leadless pacemaker CRT-P, CRT-D ICD, sicd Paced rhythm recognition: AV pacing DDD / 60 / 120

11 Paced rhythm recognition: atrial sensing, ventricular pacing DDD / 60 / 120 Paced rhythm recognition: atrial pacing, ventricular sensing DDD / 60 / 120

12 Paced rhythm recognition: atrial and ventricular sensing DDD / 60 / 120 Leadless Pacemaker Less invasive placed in the heart via a vein in the leg, thus no chest incision, scar, or bump that results from conventional pacemakers. Self-contained completely selfcontained within the heart. It eliminates potential medical complications arising from a chest incision i i and from wires running from a conventional pacemaker into the heart. Small 90-95% smaller than conventional pacemakers, about the size of a large vitamin capsule Mayo Clinic, Cleveland Clinic, Medtronic Inc.

13 What s new in pacing and ICDs? Emphasis on avoiding unnecessary RV pacing MRI compatible devices Expanded indication for CRT (Class I, II) Multipoint pacing and fusion algorithms in CRT Emphasis on avoiding inappropriate ICD shocks Leadless pacemaker and totally subcutaneous ICD AV Search Hysteresis Promotes patient s intrinsic conduction During the search, lengthens the AV delay for % of the programmed value for up to 8 cardiac cycles Search frequency programmable from 32 to 1024 cycles Up to 8 Search Cycles (Boston Scientific)

14 MVP Basic Operation DDD(R) Switch Ventricular support if loss of A-V conduction is persistent RV apical pacing

15 Prevalence and Prognosis of Ventricular Dyssynchrony LBBB More Prevalent with Impaired LV Systolic Function Preserved LVSF (1) 8% Increased All-Cause Mortality with Wide QRS at 45 Months (3) P < % Impaired LVSF (1) 24% 34% Mod/Sev HF (2) 1. Masoudi, et al. JACC 2003;41: Aaronson, et al. Circ 1997;95: % QRS < 120 ms QRS > 120 ms 3. Iuliano et al. AHJ 2002;143: Coronary sinus venogram, LAO projection

16 Long LV-RV interelectrode distance predicts response to CRT

17 AUTOMATED LV PACING VECTOR ASSESSMENT The following increased significantly with prolongation of RV-LV delay (p < 0.05). 1 Reduction in LV volumes Improvement in ejection fraction Improvement in Quality of Life (QoL) Studies suggest an intrinsic RV-LV delay > 80 ms is a suitable target for LV pacing site selection. 2,3 1 Gold MR, et al. JACC: Clin Electrophysiol. 2016;2: D'Onofrio A, et al. J Cardiovasc Electrophysiol. 2014;25: Stabile G, et al. Heart Rhythm. 2015;12: Biventricular pacing

18 LV pacing ahead of RV pacing Cardiac Resynchronization Therapy (CRT) In patients with LV dysfunction +/- CHF, intraventricular conduction delay (*LBBB, QRS>120-*150 ms), and EF <30-35%, CRT is safe and well tolerated improves quality of life, functional class, exercise capacity improves cardiac structure and function reduces mortality and hospitalization rate for CHF

19 Wireless home monitoring is standard of care for all devices What Does Optimal Device Therapy for HFrEF Look Like in 2018? Well placed quadripolar lead Capability for multipoint pacing and selfmonitoring LV capture Heart failure diagnostics MRI compatibility Systematic outpatient evaluation of nonresponders

20 Magnitude of Sudden Cardiac Arrest in the U.S. Stroke 3 Lung Cancer 2 Breast Cancer 2 HIV 1 167, ,400 40,600 42,156 Sudden cardiac arrest claims more lives each year than these other diseases combined 450,000 Sudden Cardiac Arrests 4 #1 Killer in the U.S. 1 U.S. Census Bureau, Statistical Abstract of the United States: American Cancer Society, Inc., Surveillance Research, Cancer Facts and Figures Heart and Stroke Statistical Update, American Heart Association. 4 Zheng Z. Circulation. 2001;104: Crescendo non-sustained VT (NSVT) may precede VF

21 Sustained Monomorphic VT ICD: Indications Secondary prevention: VF not due to acute MI; sustained monomorphic VT (esp. with structural heart disease and low ejection fraction); syncope with inducible sustained VT at EPS Primary prevention: NSVT with inducible sustained VT at EPS, EF < 30% and CAD, EF < 35% with CHF, familial sudden death

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24 Implantable Device Complications Infection, DVT, need for early surgical revision, device recall, bleeding, pneumothorax: total incidence about 5% Uncomfortable shocks (ICD): 20% or more from SVT alone Failure to find satisfactory lead position (CRT): 10%

25 Implantable devices can be affected by EMI Perioperative management issues related to Bovie, esp. above the umbilicus (2011 HRS/ASA guidelines) EMI inhibits pacing, triggers ICD shocks Donut magnets force pacing in pacers (not ICDs), and inhibit ICD tachyarrhythmia detection Doctor! My device shocked me! What do I do? One or two shocks and patient feels fine: call us the next day; use remote follow-up if applicable. Patient feels poorly or multiple shocks: go to ER to rule out acute ischemia, decompensated CHF, rapid AFib, hypokalemia etc. Apply donut magnet for multiple inappropriate shocks.

26 Doctor! My device has been recalled! What do I do? Risks are usually low; many patients can be managed conservatively (e.g. intensified follow-up). Selected patients who are pacemaker dependent or at high risk of sudden death may require prophylactic pulse generator or electrode replacement. Only 1 person in 20 typically survives an out of hospital cardiac arrest With an ICD, 19 out of 20 people will survive