**2. Definitions and principles of telecardiology applicable to ICDs**

*Telecardiology or home monitoring of ICDs* refers to remote communication technology in gen‐ eral. Different types of data transmission are available.

### **2.1. Type of transmissions**

*Remote follow-up* refers to programmable scheduled transmissions in which routine CIED pa‐ rameters are collected remotely in a format similar to that obtained during a routine clinic visit. As opposed to trans-telephonically monitoring, practically all information available

during traditional ICD interrogation with a programmer can be obtained via remote followup for a better outcome of patients [4-5]

Alert notifications are sent to physicians via pager, fax, SMS, voice message, or email. Many systems require access to a dedicated (device or company specific) website to obtain detailed

Remote reprogramming of alert level (yellow or red) is possible but remote ICD program‐ ming is not yet available in clinical practice, mainly due to safety considerations regarding

ICD compatible with home monitoring use radiofrequency telemetry to send information to a home communicator. This feature allows also the device to be operated remotely on a short distance (3 to 7 meters) during implantation procedure hence more flexibility, shorter intervention time, and lower risk of infection.[8] Radiofrequency telemetry is also very use‐ ful during in person follow up, eliminating the need for patient preparation and ECG moni‐ toring in most cases, all information being accessible via the programmer (figure 2). Unfortunately, this possibility of short distance remote ICD interrogation and programming

> **Medtronic CareLink**

Analogue phone line and GSM network

SMS, email, fax SMS, email Fax, email, SMS

10 s 30 s 10 s 30 s 7 s

Yes Yes Yes Yes CE yes

Yes Yes with an

antenna

**St Jude Merlin.net Sorin SMARTVIEW**

Analogue phone line and GSM network

ICD in the Era of Telecardiology http://dx.doi.org/10.5772/53361 95

Fax, email, SMS

FDA (in progress)

no

Analogue phone line, cellular network and WiFi

and automated phone calls

information on the interrogation.

data protection and unauthorized control of device function.

is not fully available for all brands at this time. (table 1)

**Biotronik Home Monitoring**

GSM network (Europe & USA), Analogue phone line (USA &Japan) 3G (Japan)

**Boston Scientific Latitude**

phone line.

Fax, phone, email

Yes Yes

**Table 1.** Comparaison of communications features

(available in 2012)

Network Analogue

Physician notification

IEGM (real-time at remote follow-up)

FDA and CE Mark system approval

Short distance RF

remote programming

*Remote monitoring* is an alert function. It refers to data acquired automatically with unsched‐ uled transmissions of any pre-specified alerts related to device functioning or to clinical events. The latter adds a new functionality to implanted devices, opening a new era of po‐ tentially beneficial pre-emptive interventions that may alter the natural history of a particu‐ lar disease or condition. [6-7].

*Patient-initiated interrogations* refers to non-scheduled follow-up interrogations as a result of a patient experiencing a real or perceived clinical event, for which the patient is seeking ex‐ pert evaluation.

#### **2.2. Technology of transmission**

Unlike traditional follow up that implies a clinic appointment, transportation and face to face meeting, remote follow up is based on Data transmitted from the device to the home monitoring station by wireless communication or using a telemetry head (for older models) between device and home monitoring station. This home monitor is linked by telephone (*analogic line or GSM* ) to a central server or website automatically to deposit encrypted data for further analysis (figure 1).

**Figure 1.** In clinic follow up (a) needs scheduling and transportation while Remote communication (b) is performed by a radiofrequency transmitter circuitry integrated in the ICD utilizing telephone lines or cellular phone technology. The ICD transfers encrypted data via the Transmitter to a service centre using a cellular network. The service centre pro‐ vides a cardiologic report accessible online by the physician via a secure Internet access

Alert notifications are sent to physicians via pager, fax, SMS, voice message, or email. Many systems require access to a dedicated (device or company specific) website to obtain detailed information on the interrogation.

Remote reprogramming of alert level (yellow or red) is possible but remote ICD program‐ ming is not yet available in clinical practice, mainly due to safety considerations regarding data protection and unauthorized control of device function.

ICD compatible with home monitoring use radiofrequency telemetry to send information to a home communicator. This feature allows also the device to be operated remotely on a short distance (3 to 7 meters) during implantation procedure hence more flexibility, shorter intervention time, and lower risk of infection.[8] Radiofrequency telemetry is also very use‐ ful during in person follow up, eliminating the need for patient preparation and ECG moni‐ toring in most cases, all information being accessible via the programmer (figure 2). Unfortunately, this possibility of short distance remote ICD interrogation and programming is not fully available for all brands at this time. (table 1)


**Table 1.** Comparaison of communications features

during traditional ICD interrogation with a programmer can be obtained via remote follow-

*Remote monitoring* is an alert function. It refers to data acquired automatically with unsched‐ uled transmissions of any pre-specified alerts related to device functioning or to clinical events. The latter adds a new functionality to implanted devices, opening a new era of po‐ tentially beneficial pre-emptive interventions that may alter the natural history of a particu‐

*Patient-initiated interrogations* refers to non-scheduled follow-up interrogations as a result of a patient experiencing a real or perceived clinical event, for which the patient is seeking ex‐

Unlike traditional follow up that implies a clinic appointment, transportation and face to face meeting, remote follow up is based on Data transmitted from the device to the home monitoring station by wireless communication or using a telemetry head (for older models) between device and home monitoring station. This home monitor is linked by telephone (*analogic line or GSM* ) to a central server or website automatically to deposit encrypted data

**Figure 1.** In clinic follow up (a) needs scheduling and transportation while Remote communication (b) is performed by a radiofrequency transmitter circuitry integrated in the ICD utilizing telephone lines or cellular phone technology. The ICD transfers encrypted data via the Transmitter to a service centre using a cellular network. The service centre pro‐

vides a cardiologic report accessible online by the physician via a secure Internet access

up for a better outcome of patients [4-5]

lar disease or condition. [6-7].

**2.2. Technology of transmission**

for further analysis (figure 1).

pert evaluation.

94 Cardiac Defibrillation

An hemodynamic measurement modification, a low rate of resynchronisation should lead physicians to look for an aetiology (e.g. atrial fibrillation, Av delay, crosstalk…) in order to

ICD in the Era of Telecardiology http://dx.doi.org/10.5772/53361 97

Development of persistent atrial fibrillation with fast ventricular rate close to ventricular fibrillation (VF) zone, frequent episodes of ventricular tachycardia (VT) with delivery of frequent antitachycardiac pacing sequences, should also act as a trigger for a follow up visit in order to change ICD parameters (VT, VF Zones, discrimination algorithms), or

This is a remote telemetry device able to communicate with the ICD automatically in real time or at scheduled intervals, and that transmits the encrypted data over long distances uti‐ lizing telephone lines or cellular phone technology. The data are then entered and stored in dedicated servers that act as data repositories and communicate actively or passively with the caregivers of the patient. A specific home communicator was developed by each compa‐ ny: Medtronic Care- Link, Boston Scientific Latitude, Biotronik Home Monitoring, Sorin Smart View and St Jude Merlin@Home.net. In the near future, all systems will be compatible with GSM. Besides, Biotronik offers complete mobility of the home monitoring station with battery backup. Furthermore, frequency of remote follow up, and selection of remote moni‐

Because of the burden of follow-up of ICD patients, with regular in-office visits every 3-6 months, puts on specialized electrophysiology clinics Heidbuchel et al. [19] retrospectively evaluated in 1739 ICD visits in a random set of 169 patients. The standard follow-up scheme consisted of in office visits 1 month after implantation and then every 6 months, unless ap‐ proaching battery depletion. They conclude that ICD remote monitoring can potentially di‐ agnose 99.5% of arrhythmia or device-related problems if combined with a follow-up by the local general practitioner and/or referring cardiologist. Its use may provide a way to signifi‐ cantly reduce in-office follow-up visits that are a burden for both hospitals and patients. A similar study was performed by Elsner et al. [20]. They investigated in a prospective, randomized, and multicentre comparison study the effect of ICD home monitoring against conventional follow-up in 115 MADIT II patients. The results prove that the simplified ICD follow-up scheme with additional home monitoring in MADIT II patients can reduce the

In 2011 Boriani et al. published a survey [21] indicating that in 'real-world' clinical practice, the follow-up of CIEDs requires important resources in terms of time dedicated by special‐

avoid a cardiac heart failure.

**2.4. Home monitor communicator**

toring alerts are fully programmable in all systems

number of visits and lead to time reduction.

**3. Advantages and challenges of telecardiology**

drug therapy.

**3.1. Physicians**

#### **2.3. Types of alerts**

The ability of implantable devices to continuously monitor variables such as heart rate, [9,10] the patient's daily activities, [11] intrathoracic impedance for the detection of fluid ac‐ cumulation, [12] the occurrence of arrhythmias [13,14] and the integrity of the system [15] may provide early warning of changes in cardiac status or of safety issues and allow timely management. When these patients have clinical events such as ICD shocks or device audible alert notifications of possible critical situations, they often visit the emergency department or clinic for an unscheduled examination.

ICD and lead dysfunction may be associated with severe consequences and could be antici‐ pated thanks to home monitoring alerts. Patients could be contacted to correct the problem in office for reprogramming or in hospital if a procedure is needed. [16-17]

Significant change in lead impedance, pacing or sensing thresholds, could be linked to lead failure and should be investigated thoroughly. It has been reported that remote monitoring helps prevent inappropriate shocks in a population at risk. [18]

An hemodynamic measurement modification, a low rate of resynchronisation should lead physicians to look for an aetiology (e.g. atrial fibrillation, Av delay, crosstalk…) in order to avoid a cardiac heart failure.

Development of persistent atrial fibrillation with fast ventricular rate close to ventricular fibrillation (VF) zone, frequent episodes of ventricular tachycardia (VT) with delivery of frequent antitachycardiac pacing sequences, should also act as a trigger for a follow up visit in order to change ICD parameters (VT, VF Zones, discrimination algorithms), or drug therapy.

#### **2.4. Home monitor communicator**

This is a remote telemetry device able to communicate with the ICD automatically in real time or at scheduled intervals, and that transmits the encrypted data over long distances uti‐ lizing telephone lines or cellular phone technology. The data are then entered and stored in dedicated servers that act as data repositories and communicate actively or passively with the caregivers of the patient. A specific home communicator was developed by each compa‐ ny: Medtronic Care- Link, Boston Scientific Latitude, Biotronik Home Monitoring, Sorin Smart View and St Jude Merlin@Home.net. In the near future, all systems will be compatible with GSM. Besides, Biotronik offers complete mobility of the home monitoring station with battery backup. Furthermore, frequency of remote follow up, and selection of remote moni‐ toring alerts are fully programmable in all systems
