The Japan Association of Remote Exercise Therapy (JARET) has developed remote cardiac rehabilitation services to prevent recurrence and improve prognosis in the maintenance phase of heart disease. This report examines challenges such as service delivery models, program design, educational integration, quality assurance, and cost management. Based on JARET’s operational experience, we explore feasible strategies for sustainable implementation and organizational management to support broader adoption of remote rehabilitation.

　esCCO (estimated Continuous Cardiac Output) is a method that continuously estimates cardiac output using PWTT (pulse wave transit time) derived from electrocardiograms and pulse waves obtained through SpO₂ monitoring. These are regularly measured in operating rooms and intensive care units. This method is entirely noninvasive and involves no additional cost.

　The use of pulse wave velocity for diagnosing arterial stiffness has a long history and has been implemented in practice, including through sensor development. Based on knowledge gained from this application, esCCO was developed to apply PWTT to primary and critical care monitoring.

　The development followed the trajectory described below. It was known that the pulse wave velocity between two arterial points is influenced by the degree of arterial stiffness and blood pressure. Therefore, if arterial stiffening progresses slowly, it was hypothesized that blood pressure could be estimated from PWTT once calibrated. Furthermore, a simple method for continuous measurement was required. Under these circumstances, PWTT-based blood pressure estimation was put into practical use, although it faced the limitation of decreased accuracy during the administration of vasoactive drugs.

　On the other hand, this limitation does not apply when focusing on the relationship between PWTT and SV (stroke volume). Furthermore, when the endpoint of PWTT measurement is defined using pulse oximetry waveforms, the time it takes for the waveform to reach peripheral sites varies depending on the diameter of peripheral blood vessels. This variation was found to contribute to improved accuracy in measuring SV.

　This review article provides an overview of esCCO and then explains three key ideas that led to its development.

　Objective and Methods: To evaluate the exercise tolerance of 78 residents of a nursing home (NH) in Japan (age 91.8±5.8 yrs), 20 outpatients who were provided day services (88.3 ± 7.6 yrs), and 16 home-residing individuals who required visiting rehabilitation (age 88.1 ± 5.8 yrs), we measured the grip strength of each participant and evaluated the relationships among their ages, the NH residents’ serum Ca concentrations (8.8 ± 0.4 mg/dL), and the severity of the NH residents’ need for care (2.9±1.3 points). The larger of the right- or left-side grip strength measurements were used.

　Results: The NH residents’ grip strength values were: right 10.1 ± 3.0 kg, left 10.3 ± 3.5 kg. The outpatients’ values were: right 13.0±4.8 kg and left 14.0±5.7 kg, while the residents’ values were right 14.7 ± 5.1 kg and left 13.5 ± 4.5 kg. There were significant correlations between age and grip strength for the right side (−0.579, p＝0.0118), left side (r＝− 0.557, p＝0.0163), and the larger values of the left vs. right (r＝− 0.649, p＝0.0002).

　Conclusion: For the residents of a nursing home and the users of its related services, the measurement of grip strength was useful for evaluating exercise tolerance prior to the initiation of rehabilitation.

　This case report details the case of a male diagnosed with Becker muscular dystrophy (BMD) at 20 years of age. From the age of 33 years, the patient experienced recurrent episodes of heart failure and was subsequently diagnosed with dilated cardiomyopathy. At 42 years of age, the patient underwent left ventricular assist device (LVAD) implantation. Resistance training can cause muscle damage in patients with BMD, and endurance training alone is often insufficient to improve muscle strength. Postoperatively, a cardiac rehabilitation (CR) program centered on low-intensity interval training (LIIT), ―consisting of four sets of 3 min of exercise at 20 watts followed by 1 min of rest at 0 watts, ―was initiated. Observed treatment outcomes included improved body mass index, muscle strength, and walking ability. Following heart transplantation, the patient recovered well, was discharged, and successfully returned to society, where he now assists other patients with LVADs. LIIT in a patient with BMD and a LVAD was effective in preventing a decline in activities of daily living (ADL) and improving, ADL and quality of life after heart transplantation.