Introduction
Methods
Patient selection
Enrolled | Age | Gender (M/F) | LVEF % | |
---|---|---|---|---|
Controls | 22 | 40 ± 13 | 16/6 | 61 ± 8 |
CAD (no MI) | 24 | 65 ± 8 | 17/7 | 62 ± 8 |
CHD (previous MI) | 28 | 64 ± 9 | 23/5 | 50 ± 14 |
DCM | 10 | 68 ± 9 | 8/2 | 39 ± 8 |
Hypertension | 13 | 60 ± 7 | 8/5 | 61 ± 9 |
COPD | 18 | 62 ± 12 | 15/3 | 61 ± 3 |
Valvular disease | 14 | 59 ± 15 | 8/6 | 60 ± 11 |
Corrected congenital | 13 | 28 ± 14 | 5/8 | 46 ± 32 |
Diagnostic | 30 | 48 ± 16 | 18/12 | 58 ± 10 |
Semi-supine bicycle exercise
Post-exercise
Regional wall motion analysis
Diagnostic end points and interruption criteria
Blood pressure analysis
Echocardiographic hemodynamic assessment
Measured values (rest, peak stress, recovery min. 1, 3, 5) | Method | Measure unit |
---|---|---|
Heart rate | ECG |
bpm
|
LV ESV index | 2D echo (Simpson rule)/BSA |
mL/m
2
|
LV EDV index | 2D echo (Simpson rule)/BSA |
mL/m
2
|
SBP | Sphygmomanometer |
mmHg
|
DBP | Sphygmomanometer |
mmHg
|
Calculated values
(rest, peak stress, recovery min. 1, 3, 5)
| ||
Stroke volume index | EDV index – ESV index |
mL/m
2
|
Cardiac index | stroke volume index * heart rate |
L/min/m
2
|
Mean Arterial Pressure | (SBP-DBP)/3 + DBP |
mmHg
|
LV elastance index | SP/ESV index |
mmHg/mL/m
2
|
Effective arterial elastance index (EaI) | (SBP*0.9)/Stroke volume index |
mmHg/mL/m
2
|
Ventricular-arterial coupling | LV elastance index/Eai |
ratio
|
SVR index
|
80 * (MAP-5)/Cardiac index
|
dyne * sec * cm
5
|
Contractility, diastolic time, and arterial pressure measurements by precordial cutaneous sensor
Sensor-based intelligent monitoring as a model of a wireless telemedicine system
Statistical analysis
Results
Stress echo results
Comparison between sensor and echo assessment in 52 subjects
Sensor-based force-frequency relation, diastolic time-frequency relation and derived systemic pressure in the post-exercise phase in the 172 enrolled subjects
The post-exercise force frequency relation and the contractile overshoot
Diastolic time-frequency relation and the post-exercise diastolic time overshoot
Sensor-derived systemic pressure and post-exercise hypotension
Discussion
Comparisons between sensor- and echo-derived information on function during recovery
Sensor-based post-exercise force-frequency relation in normal and diseased hearts
Sensor-based diastolic time-frequency relation in the post-exercise
Systemic pressure in the post-exercise phase and sensor-monitored pressure changes
Clinical implications, implantable vs. wearable sensors and chronic heart failure
Implantable hemodynamic monitors (IHMO)
Wearable sensors
The systolic and diastolic FFR sensor
Clinical status | Force-Frequency Relation (FFR) | Diastolic time-frequency relation | S2-frequency relation |
---|---|---|---|
Normal | Upsloping FFR | systolic/diastolic time ratio < 1 | Normal upsloping |
Normal recovery | Normal recovery | Recovery undershoot | |
Acute ischemia | Acute biphasic FFR | Acute systolic/diastolic time ratio > 1 | Acute S2 blunting |
Recovery overshoot | Recovery overshoot | Recovery overshoot | |
CHF worsening ↓ | 1- Blunted FFR slope | ||
↓↓ | 2- From upsloping to biphasic FFR | Systolic/diastolic time ratio > 1 at lower HR | S2 blunting |
↓↓↓ | 3- Lower critical HR in biphasic FFR | ||
- Recovery overshoot | Recovery overshoot | ||
CHF improving ↑↑↑ | 3- Upsloping FFR | ||
↑↑ | 2- From biphasic to upsloping FFR | Systolic/diastolic time ratio > 1 at higher HR | Upsloping S2 |
↑ | 1- Higher critical HR in biphasic FFR | ||
- Normal recovery | Upsloping S2 | ||
Hypertension/diastolic failure | Blunted FFR | Systolic/diastolic time ratio > 1 at lower HR | Steeper S2 curve |
Recovery overshoot | Recovery overshoot | Recovery overshoot | |
Atrial fibrillation | Preceding and pre-preceding interval FFR dependence | Systolic/diastolic time ratio scattering | S2 scattering |