Most Relevant Technological Advancements of Recent Years in Cardiac Pacing Dr. Sebastian Gallino Electrophysiology Sector. Cardiology Service. Cosme Argerich Hospital

Evolution of implantable cardiac devices

Most relevant technological advancements in cardiac pacing 1)Control and follow up all the time and from anywhere in the world. Remote monitoring from a distance of pacemakers and cardioverter defibrillators.

Remote monitoring from a distance of pacemakers and cardioverter defibrillators This new technology applied to medicine permits monitoring in a remote way, the cardiac rhythm of the patient through such device, which can send automatically once a day and immediately in the case of a critical event, by a cell phone network (GPRS system), the information stored for a while, or when cardiac rhythm disturbances appear

This medical and technical information is sent to a service center, where it becomes a brief report that is immediately submitted through the Internet, SMS or by fax, to the attending physician, which allows to the latter, to be in touch with the patient and better monitor cardiac rhythm and the capacity of operation of the device implanted in each patient Remote monitoring from a distance of pacemakers and cardioverter defibrillators

As an additional feature, the system also detects possible technical failures in the device, such as for instance, low signal quality that could interfere with the accuracy of a future management. Another interesting item of this technology is the possible improvement of life span of the ICD as a result of a decreased number of unnecessary electrical shocks. Remote monitoring from a distance of pacemakers and cardioverter defibrillators

Benefits: -Early diagnosis of asymptomatic atrial fibrillation, appropriate and inappropriate shocks, alterations in catheter state and the battery. Reduced controls in person without increasing risk (1) -Early management when faced with pathologic findings without waiting for the next scheduled routine follow up. (1) Circulation. 2010;122: Efficacy and safety of automatic remote monitoring for implantable cardioverter-defibrillator follow-up. The Lumos-T safely reduces routine office device follow-up (TRUST) trial Remote monitoring from a distance of pacemakers and cardioverter defibrillators

2) Early detection of Atrial Fibrillation and Ventricular Arrhythmia. Storing of atrial fibrillation recordings (AF load), ventricular arrhythmias, etc. “Stored electrograms” Most relevant technological advancements in cardiac pacing

Stored electrograms The contribution to routine telemetric controls, allows storing information with clinical relevance for making daily decisions faced with the patient

Storage of EGMs ventricular tachycardia ventricular tachycardia (rate/duration) (rate/duration) NSVT (3 or more PVC) NSVT (3 or more PVC) tachy-atrial response tachy-atrial response tachy-atrial detection tachy-atrial detection (rate/duration) (rate/duration) sudden response to brady sudden response to brady magnet magnet pacemaker-mediated pacemaker-mediatedtachycardia

Storage of information

Atrial Fibrillation Detection

Example: Syncopal ventricular tachycardia

Stored episode of atrial arrhythmia at 200 bpm. Example: Atrial flutter 50 mm/sec

9 seconds Patient dependent on ventricular pacing

3) Decrease of shocks and their deleterious effect. Anti-tachycardia pacing of ventricular tachyarrhythmias in patients carriers of ICD. Most relevant technological advancements in cardiac pacing

Cardioverter defibrillators have a primary function, i.e. prevention of sudden cardiac death by interrupting ventricular tachyarrhythmias This function is made by intracavitary electric shock or by non-painful therapy known as anti-tachycardia pacing

This system paces the ventricle at heart rates slightly greater than the cycle length of tachycardia and enables interrupting it It has the benefit of preventing the traumatic and painful effect of the shock, which is proven worsens quality of life, permits prolonging longevity of the generator, and on the other hand, preventing the deleterious effect of it in some given populations of patients

Numerous studies have consistently shown that -anti-tachycardia pacing (ATP) effectively ends with ~85-90% of slow VT (CL< ms) with a low risk of acceleration of the VT (1-5%). Recent studies have shown a high rate of success and low acceleration in rapid VT (CL ms). These observations have repositioned ICD primarily as an ATP device with back up defibrillation only if required.

Effective anti-tachycardia pacing VT (CL 380 ms)Pacing Sinus rhythm

4) Greater life span of battery. Greater security of the patient. Automatic control of ventricular pacing threshold. Most relevant technological advancements in cardiac pacing

This system has the function of determining automatically and periodically the threshold of atrial and ventricular pacing by making a threshold test, similar to the one usually made as a routine control, and adjusting voltage and pulse width to minimal values with pre-established security margins (usually near twice the threshold)

This function has as benefits the proven increase of longevity of the pulse generator, therefore less exchanging–less interventions and the security-protection of the patient before the acute or chronic increase of pacing threshold by different reasons, e.g. anti-arrhythmic medication, myocardial infarction, etc.

Capture verification-security patient Patient A Patient B

Autocapture algorithm Capture is determined by the detection of the evoked response (ER) of the catheter tip (produced by the local capture of the myocardium) It seeks ER in each beat If ER is not observed, it emits a security pulse –4.5 V and 0.5 ms Pulse Width Initial Pulse Loss of Capture Back up Pulse

Initial Pulse Back-Up Safety Pulse Algorithm Loss of capture, a beat

Detail of automatic control of capture

5) Preventing unnecessary pacing and its deleterious effect. Decrease of pacing from the right ventricular tip. Most relevant technological advancements in cardiac pacing

Different published studies in recent years have shown a deleterious effect of ventricular pacing from the RV apex in given populations (1,2,3), for this reason the industry of devices has developed algorithms to prevent the unnecessary pacing when this could be prevented. (1,2,3) The Mode Selection Trial (MOST) Investigators.. Adverse effect of ventricular pacing on heart failure and atrial fibrillation among patients with normal baseline QRS duration in a clinical trial of pacemaker therapy for sinus node dysfunction. Circulation. 2003;107: MADIT II Investigators. The clinical implications of cumulative right ventricular pacing in the multicenter automatic defibrillator trial II. J Cardiovasc Electrophysiol Apr;16(4): Effect of chronic right ventricular apical pacing on left ventricular function. Am J Cardiol. 2005;95:771-3.

The DAVID study “Dual Chamber and VVI Implantable Defibrillator (DAVID) Trial” (1) compared CDI -DDD vs. CDI -VVI in 506 patients with conventional indication of ICD without indication of antibradycardia pacing with ejection fraction lower or equal to 40%. Patients with DDD and greater percentage of RV pacing had a greater risk of death and/or HF hospitalization. (1)Dual-chamber pacing or ventricular backup pacing in patients withan implantable defibrillator: the Dual Chamber and VVI Implantable Defibrillator (DAVID) Trial. JAMA. 2002; 288:

The DAVID Trial P=0.03 DDDR VVI Months to death or first hospitalization for CHF Cumulative Probability Number at risk: DDDR VVI Wilkoff BL. JAMA 288: 3115–3123, 2002

DAVID subanalysis Sharma AD. Heart Rhythm 2: , 2005 DDDR>40% VVI Months % with Primary Endpoint DDDR≤40% Number at risk: DDDR>40% VVI DDDR≤40% DDDR>40% vs. DDDR<40%p=0.03 DDDR>40% vs. VVI p=0.07

Gentileza de Medtronic)

Is Dual Chamber Programming Inferior to Single Chamber Programming in an Implantable Cardioverter Defibrillator? INTRINSIC RV Study Results Brian Olshansky, John D. Day, Stephen Moore, Lawrence Gering, Murray Rosenbaum, Maureen McGuire, Scott Brown, Darin R. Lerew. (Pace 2006,29: )

Primary end point p<0.001, noninferiority

6) Greater clinico-therapeutic control in patients with CHF. Measurement of intra- thoracic impedance. Most relevant technological advancements in cardiac pacing

CHF is one of the most frequent causes of hospitalizations between people older than 60 years old. In spite of therapeutic advances, most of these patients have hospitalizations by decompensation of chronic CHF.

Most of these hospitalizations are due to pulmonary liquid accumulation, so that an early detection of volume enlargement and pulmonary congestion would allow the timely adjustment of the treatment, thus preventing hospitalizations, associated morbi-mortality and related costs.

The Medtronic company has added in cardioverter defibrillators and resynchronizers, the measurement of intrathoracic impedance, an efficient parameter to follow daily changes in the state of the edema and pulmonary volume.

Faced with the increase of this impedance, the device by an audible signal, alerts the patient to make an early consultation and to the physician to establish a more aggressive treatment. Different studies have shown that it predicts CHF worsening (1,2) ( 1,2 ) Changes in intrathoracic impedance are associated with subsequent risk of hospitalizations for acute decompensated heart failure: clinical utility of implanted device monitoring without a patient alert. J Card Fail. August 2009;15(6): [OFFISER] Superior performance of intrathoracic impedance-derived fluid index versus daily weight monitoring in heart failure patients. Results of the Fluid Accumulation Status Trial. Late Breaking Clinical Trials. J Card Fail. Vol. 15 No , p 813.[FAST]

7) Cardiac Resynchronization Therapy. Electric treatment of heart failure (it will be dealt with in another presentation of this symposium) Most relevant technological advancements in cardiac pacing

Conclusions Technological advancements in implantable cardiac devices are very extensive; in this report, we quote those considered of greatest clinical impact. We should mention that there are other types of developments such as smaller batteries with a longer life span, evolution of catheters, advancements in programming, devices with protection for NMR, telemetric control from a distance, just to mention a few.