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[The re-evaluation of the vasodepressive component in the carotid sinus syndrome]
G Gaggioli1, M Brignole, C Menozzi
1Servicio di Cardiologia, Ospedale di Lavagna.
Insights
The vasodepressor (VD) reflex in carotid sinus syndrome is significant and prolonged, especially in the VD form. Non-invasive beat-to-beat monitoring accurately assesses this reflex, highlighting its importance in patient management.
Area of Science:
- Cardiology
- Neuroscience
- Physiology
Background:
- Carotid sinus syndrome (CSS) diagnosis is often hindered by inaccurate blood pressure measurement during vasodepressor (VD) reflex evaluation.
- The VD reflex plays a crucial role in CSS, but its precise assessment remains challenging.
Purpose of the Study:
- To investigate the VD reflex in CSS using a non-invasive, beat-to-beat monitoring technique.
- To differentiate the VD reflex characteristics across various CSS subtypes (cardioinhibitory, mixed, VD forms).
Main Methods:
- Sixty-eight CSS patients and 9 control subjects underwent carotid sinus massage while beat-to-beat systolic blood pressure was monitored using the Finapres photoplethysmographic technique.
- Patients were categorized into cardioinhibitory (CI), mixed (M), and VD forms of CSS.
- Control group comprised pacemaker-dependent patients with atrioventricular block.
Main Results:
- Carotid sinus massage induced a significant drop in systolic blood pressure across all CSS forms, with a decrease >= 50 mm Hg in 84% of cases.
- Patients with the VD form exhibited a significantly lower systolic blood pressure for over 27 seconds post-massage compared to other groups.
- While the initial blood pressure fall was similar across CSS forms, the duration and magnitude of the decrease were most pronounced in the VD form.
Conclusions:
- The VD reflex is a significant and prolonged component of CSS, extending beyond the cardioinhibitory reflex.
- Non-invasive beat-to-beat monitoring effectively characterizes the VD reflex in CSS.
- The findings underscore the critical importance of evaluating the VD reflex in CSS patients, particularly those with the VD form.
Background:
The evaluation of the vasodepressor (VD) reflex of the carotid sinus syndrome is usually inaccurate, due to the difficulty in blood pressure measurement.
Aim:
To study the VD reflex with a beat-to-beat not invasive technique.
Methods:
We investigated 68 patients (49 males, 19 females; mean age 70 +/- 11 years) affected by carotid sinus syndrome: cardioinhibitory (CI) form was present in 47 patients, mixed (M) form in 10 patients and VD form in 11 patients. The control group consisted of 9 patients (6 male, mean age 71 +/- 8 years) affected by third degree atrioventricular block who had received the implant of a permanent pacemaker and were pacemaker-dependent with a prolonged asystole at time of temporary inhibition of the pacemaker itself. The study of the VD reflex was performed in the supine position; beat-to-beat arterial systolic pressure was monitored by a photoplethysmographic method using a finger cuff (Finapres technique).
Results:
In all the patients the carotid sinus massage caused a marked fall in systolic blood pressure which was greatest at the end of the massage: from 143 +/- 25 mm Hg to 74 +/- 20 mm Hg in the patients with CI form, from 144 +/- 14 mm Hg to 76 +/- 18 mm Hg in those with M form and from 125 +/- 26 mm Hg to 65 +/- 13 mm Hg in those with VD form. A decrease in systolic blood pressure > or = 50 mm Hg occurred in 84% of cases. Afterwards, the patients with CI form had a progressive increase of systolic blood pressure that reached the initial value after a mean of 27 seconds. In the patients with VD form systolic blood pressure was significantly (p < or = 0.5) lower than that observed in all the other groups, beginning from the third second after the end of the massage; mean systolic blood pressure value remained significantly lower than the initial value for more than 27 seconds. The patients with M form showed an intermediate pattern. Also control group patients showed a fall in systolic blood pressure immediately after pacemaker inhibition (from 152 +/- 29 mm Hg to 87 +/- 25 mm Hg) that was of similar extent than that observed in carotid sinus syndrome patients, but pressure returned to initial value within 9 seconds.
Conclusions:
An important VD reflex is present in most patients with carotid sinus syndrome. It lasts more than the CI reflex and it persists for several seconds after the end of the massage. The initial fall of systolic blood pressure is of similar extent in all the forms of carotid sinus syndrome, but the patients with the VD form are characterized by a longer duration and greater entity of the decrease. These results point out the importance of the VD reflex in patients with the carotid sinus syndrome.