**Jadwiga Wolszakiewicz, Jana AlQahtani, Adam Staron and Abdullah AlKhushail**

### *5.1. General Rules*

Phase III, or the maintenance phase, contains a program that typically starts within the cardiac rehabilitation center and is continued at the local fitness center, gym, or the patient's home.

The objective of phase III is to provide guidance and support for a continuous lifestyle change [1]. Phase III involves more independence and self-monitoring, shifting a center-based program into a home-based environment. Therefore, the transition between structured phase II and long-term phase III can be a vulnerable point due to the risk for non-adherence to recommended pharmacological treatment and lifestyle modifications, including physical activity. As expected, adherence to phase III of cardiac rehabilitation is poor, and barely 20–30% of patients continue exercise after a year of discharge from phase II [2]. This relates to individual- and environmental-level barriers that lead to poor adherence to physical activity plans. These barriers include, e.g., lack of time, lack of motivation, work tasks, social obligations, or unfavorable weather [3].

Prescribing an individually tailored physical activity plan that takes into consideration the underlying cardiac condition and cardiorespiratory fitness level is essential. Utilizing digital tools, e.g., wearable physical activity monitors, should help to maintain long-term adherence to physical activity. The authors recommend the ABC model of phase III by Rudnicki, with analogous rules to those for phase II [4]. Patients with an intermediate level of risk and very low functional capacity, as well as high-risk patients with an intermediate, low, or very low functional capacity, should be treated equivalently to model D of phase II cardiac rehabilitation. Tables 40–42 exhibit the A, B, and C models of exercise prescription.


**Table 40.** Suggested A model of phase III exercise prescription for low-risk patients.

Source: Adapted from [4].

**Table 41.** Suggested B model of phase III exercise prescription for intermediate-risk patients with good exercise tolerance.


Source: Adapted from [4].


**Table 42.** Suggested C model of phase III exercise prescription for a patient with intermediate risk and low or intermediate functional capacity and for high-risk patients with good exercise tolerance.

Source: Adapted from [4].

### *5.2. Telerehabilitation*

### 5.2.1. Background

Patients' adherence to the center-based cardiac rehabilitation model remains suboptimal, with rate of participation in phase II being 40% in Europe and 30% in the United States, both an insufficient referral rate by medical professionals and a suboptimal enrollment for referred patients [5]. Multiple cardiac rehabilitation barriers have been identified, including a lack of adequate patient and healthcare provider awareness, a lack of rehabilitation center availability, and a lack of financial remuneration. Patients report that their main barriers to cardiac rehabilitation attendance are related to work and family responsibilities, financial costs, lack of motivation, or the long distance from home to cardiac rehabilitation facilities. Thus, up to one third of participants prematurely drop out of the program—these are mainly patients with coronary artery disease, older age, and lower economic status [6–8]. Alternative strategies have been developed accordingly, to resolve several barriers impeding the utilization of cardiac rehabilitation programs and creating a more active role for the patient in the whole system [9]. Historically, physical activity has been evaluated by pedometers and accelerometers, with a further rapid development of online applications providing activity tracking by smartphones and smartwatches, including heart rate, distance covered, and energy

expenditure calculation [10,11]. The recent COVID-19 pandemic has affected the traditional model of center-based cardiac rehabilitation delivery due to restrictions imposed by the authorities to prevent the spread of the infection, along with unit closure and staff redeployment [12–14]. This emergency triggered the rapid development of telemedicine and highlighted the role of cardiac telerehabilitation as an efficacious, safe, and essential part of cardiac rehabilitation [15]. Cardiac telerehabilitation is based on ECG-monitored exercise training at home and is controlled and modified remotely by the cardiac rehabilitation team. It entails telemonitoring, tele-advice, and direct interaction with the patient [16]. Cardiac telerehabilitation may be a continuation of an outpatient or residential program and is suitable for the following groups of patients [17]:


## 5.2.2. Technical Aspects

Patients utilize remotely controlled devices for tele-ECG monitoring, with the ECG signal being transmitted from precordial leads to a mobile phone through, e.g., Bluetooth technology. The data are then typically transmitted through a mobile phone network to the monitoring center [18]. Patients communicate with their supervising team via a mobile phone (Figure 18). Prior to commencing telerehabilitation sessions, patients initially attend an outpatient program (typically for 5–10 sessions) with clinical examination, individual training prescription, and the supervision of training progress [19]. Remote telerehabilitation sessions start with questions regarding the patient's current clinical status, followed by the transmission of resting ECG and reporting values of blood pressure and weight. Personalized training programs applied by the supervising cardiac rehabilitation team can be executed in the form of marching on the spot, walking, or training on a stationary bike. Exercise training sessions of 45–60 min duration are typically prescribed, comprising 2 to 5 sessions per week, including a warm-up phase and a cool-down phase [20]. In the case of interval training, the device notifies patients about the transition between phases through sounds, voice commands, or light signals. In addition, an alarm system will be triggered if an abnormal situation occurs, alerting the monitoring team.

**Figure 18.** Principles of remotely monitored cardiac telerehabilitation. Source: Reprinted from [19].
