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Evaluation by Cardiopulmonary Exercise Test of DDDR Versus DDD Pacing
Author(s) -
CAPUCCI ALESSANDRO,
BORIANI GIUSEPPE,
SPECCHIA SALVATORE,
MARINELLI MASSIMO,
SANTARELLI ANDREA,
MAGNANI BRUNO
Publication year - 1992
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1111/j.1540-8159.1992.tb02992.x
Subject(s) - medicine , test (biology) , cardiac pacing , cardiology , anesthesia , paleontology , biology
In eight patients (age 62 ± 6 years) a DDDR pacemaker was implanted for sick sinus syndrome (three cases) or second‐ and third‐degree AV block (five cases). In five subjects chronotropic incompetence (maximal heart rate on effort < 110 beats/min) was present before implantation. One month after implantation the patients were randomized to DDDR or DDD pacing for 3 weeks each, with subsequent crossover, and at the end of each period a symptom limited Cardiopulmonary exercise test (25 watts/2 min) was performed and the patients were requested to fill a symptoms questionnaire. Results: DDDR pacing, compared to DDD, was associated with higher maximal heart rates (127 ± 20 vs 110 ± 27 beats/min, P < 0.02), higher (VO 2 max (25.4 ± 6.1 vs 21.5 ± 7.8 mL/kg/per min, P < 0.03) and higher VO 2 at the anaerobic threshold (20.3 ± 5.0 vs 15.8 ± 4.9 mL/kg per min, P < 0.03), without significant differences in mean exercise time (526 ± 193 vs 472 ± 216 sec, NS). The increase in VO 2 max obtained in DDDR versus DDD was significantly related to the increase in maximal heart rate (r = 0.72, P < 0.05) and the increase in VO 2 at the anaerobic threshold obtained in DDDR versus DDD was related to the increase in heart rate at the anaerobic threshold (r = 0.81, P < 0.02). In patients with chronotropic incompetence the improvement obtained in DDDR versus DDD was even more significant (VO 2 max = 22.7 ± 5.9 vs 16.1 ± 4.4 mL/kg per min, P < 0.03; VO 2 at the anaerobic threshold = 18.4 ± 5.1 vs 13.2 ± 2.8 mL/kg per min, P < 0.05; exercise time = 438 ± 132 vs 352 ± 150 sec, P < 0.02). In the population as a whole, no significant differences were found relative to subjective symptoms, meanwhile in patients with chronotropic incompetence a better subjective tolerance was apparent with DDDR than with DDD pacing. In conclusion, DDDR pacing induces a significant improvement of exercice capacity, in comparison to DDD pacing, related to the ability to reach higher heart rates during exercise. This phenomenon is particulary evident in patients with chronotropic incompetence in whom DDDR pacing also is subjectively better tolerated.