As highlighted by Armando Luisi during his talk at the Congress of the Italian Society of Pacing and Electrophysiology on September 24th, the time is ripe for a paradigm change in the relationship patient – health system for those who have chronic diseases. Patients may play an active role in the disease management process, owing to progressive patients’ empowerment.
APDIC mission is to awake everyone’s capability to cooperate. Learning the vocabulary of CIEDs therapy is a good start!
PACEMAKER VOCABULARY
Pacemaker: titanium can hosting a microprocessor that provides monitoring of the cardiac rhythm and stimulation, and a battery that supplies the energy. The Pacemaker is termed Single Chamber (lead in the right atrium/ventricle only), Dual Chamber (leads in the right atrium and in the right ventricle), Biventricular or CRT-P (leads in the right atrium, in the right ventricle, and in the left ventricle)
Leads: insulated wires connecting the cardiac chambers to the ICD. Leads have a TIP and a RING electrode, about 10-20 mm spaced.
Pacing/sensing configuration: both can occur either from the TIP to the CAN (Unipolar) or from the TIP to the RING (Bipolar).
Basic Rate: minimum paced rate in Single Chamber pacemakers.
Hysteresis: minimum heart rate before pacing occurs. Once this rate is achieved, pacing occurs at the Basic Rate. Example : Basic Rate=60 bpm, Hysteresis=35 bpm. The patient intrinsic rhythm may be as low as 36 bpm. When 35 bpm is reached, pacing at 60bpm begins.
Maximum Sensor Rate: maximum rate driven by the sensor/s during exercise. Sensor-driven pacemakers are used for patients whose intrinsic rhythm cannot increase during exercise. These pacemakers are easily identified by the R code: SSIR, VVIR, VDDR, DDDR.
Lower Rate: minimum paced rate in Dual chamber or Biventricular (CRT-P) pacemakers.
Upper Rate: maximum sinus node rate tracked to the ventricle by Dual chamber or Biventricular (CRT-P) pacemakers.
AV delay: conduction time from the atrium to the ventricle. In the absence of intrinsic ventricular activity, ventricular stimulation is delivered. Available in Dual chamber or Biventricular (CRT-P) pacemakers only.
AV delay Hysteresis: interval automatically added to the AV delay to detect spontaneous AV conduction. In this occurrence, ventricular stimulation is spared.
AAI/DDD mode: enhanced avoidance of unnecessary right ventricular stimulation.
Mode Switch: automatic change to a non-tracking mode during Atrial Arrhythmias to prevent high rate stimulation of the ventricles due to the ongoing fast atrial rate. Dual chamber or Biventricular (CRT-P) pacemakers only.
Automatic Verification of Stimulation: this concept is brought into practice by several algorithms termed autocapture or autothreshold, respectively. These algorithms measure periodically the amount of current necessary to elicit effective cardiac stimulation (Pacing Threshold), and adjust the pacing output accordingly by adding a small safety margin. The effective stimulation may be checked beat-to-beat (autocapture algorithms) or at programmed intervals (autothreshold algorithms): the closer the monitoring of capture, the smaller the safety margin. The use of this stimulation modality has proved superior safety compared to a fixed-voltage output, and significantly increases pacemaker longevity.
Automatic sensing: automatic update of the sensitivity level needed to reliably detect the spontaneous cardiac signals according to its changes along time.
For more information, read also the Heart Rhythm section.
ICD VOCABULARY
Implantable Cardioverter-Defibrillator (ICD): titanium can hosting a microprocessor that provides monitoring of the cardiac rhythm and Arrhythmia termination, and a battery that provides the energy. The ICD is termed Single Chamber(lead in the right ventricle only), Dual Chamber (leads in the right atrium and in the right ventricle), Biventricular or CRT-D (leads in the right atrium, in the right ventricle, and in the left ventricle)
Leads: insulated wires connecting the cardiac chambers to the ICD. Leads have a TIP and a RING electrode, about 10 mm spaced. The right ventricular lead has one (single coil) or two (dual coil) coil/s to deliver the high voltage therapy that is necessary to terminate life-threatening ventricular Arrhythmias
Pacing/sensing configuration: for the right atrium and right ventricular lead it can be programmed bipolar only.
ATP: anti-tachycardia pacing. Overdrive stimulation that is automatically delivered by the ICD to terminate ventricular tachycardia. Effective in at least 70% of episodes. In the event of success at the first attempt, it is the fastest way to terminate a ventricular Arrhythmia.
SHOCK: High-voltage therapy automatically delivered to terminate Arrhythmias that might otherwise result in a cardiac arrest. As contraction of all the thoracic muscles may be elicited by such a high voltage impulse, it is often perceived as painful in a wide subjective range.
Remember that every ICD is a Pacemaker also: please refer to the dedicated section to learn this latter vocabulary too.
For more information, read also the Heart Rhythm section.
