Csécs, Ibolya

Background: Data on the occurrence of syncope and presyncope with hemodynamic instability during graded exercise test (GXT) are limited. Methods: We reviewed the Mayo Integrated Stress Center database for non-imaging GXTs performed between January 2006 and December 2010 and registered syncopic/presyncopic episodes. Electronic medical records were reviewed for clinical information, outcomes, and mortality. SAS was used to provide background statistics. Results: During the study period, a total of 40,715 GXTs were performed on 33,885 unique patients, including 16,306 (40.0%) GXTs on patients with known cardiovascular disease (CVD). High risk for cardiac syncope is defined as prior cardiac arrest/ventricular tachycardia, ischemic cardiomyopathy, implanted defibrillator, history of atrial fibrillation, sotalol, amiodarone, LQTS, HOCM, aortic stenosis was identified in 3263 patients (6.0%), while risk factors for non-cardiac syncope (POTS, history of dizziness/spells/syncope, rest SBP < 100 mmHg, age ≥ 80 years, female age < 30 years, beta blocker use) were found in 15,925 patients (39.1%). Despite the presence of so many patients at risk, only 8 episodes of syncope occurred (0.020% per test; 0.023% per individual patient). Another 5 episodes of near-syncope with documented hypotension were aborted by the quick action of the testing staff (0.012% per test; 0.015% per individual patient). Only 1 patient (a 71yo M with severeCAD) required electrical cardioversion for ventricular fibrillation. None of the other patients, including all 6 women, presented with tachyarrhythmias. There were no deaths and no significant musculoskeletal trauma. Conclusion: Despite many patients with risk factors for cardiac and non-cardiac syncope in the cohort, syncope, and near-syncope with hemodynamic instability were very rare findings on guideline-directed GXTs.

Introduction: Breathing efficiency (V E /VCO 2 slope or nadir) predicts mortality in heart failure (HF). The usual pattern of V E /VCO 2 vs. exercise intensity is a characteristic “shallow bowl” configuration allowing estimate of a V E vs. VCO 2 slope both in normal controls (C) and HF patients. Slope or nadir in HF is generally > 33 vs. 25-30 in C. This pattern of V E /VCO 2 may not be true for other CV diseases. Objective: Compare V E /VCO 2 versus exercise time curves in patients with history of chronic thromboembolic pulmonary hypertension type 4 (PHT4) to HF and C referred for dyspnea on exertion. Methods: We identified 40 consecutive cases of PHT4 versus 40 HF and 40 C over the same age range retrospectively selected from our cardiopulmonary exercise test (CPX) database. V E /VCO 2 was plotted against exercise time (minutes of exercise ≈ METs), and groups were compared statistically for V E /VCO 2 and peak VO 2 by ANOVA followed with Tukey test, with significance set at P < .05. Results: Figure shows higher V E /VCO 2 in PHT4 vs. HF and C with a different pattern vs. exercise intensity. In severe cases (example shown) V E /VCO 2 may increase continuously without plateau reaching peak values > 80. There was statistically significant difference between peak VO 2 between C group vs HF and PHT4, but not among HF and PHT4, although V E /VCO 2 was significant different among the three groups. Age and sex was not different among them. Conclusion: V E /VCO 2 was elevated in PHT4 compared to HF and C. We interpret continuously increasing V E /VCO 2 as a marker of progressively worsening ventilation: perfusion mismatch. Interpretation of V E /VCO 2 in PHT4 cannot be based simply on nadir or slope as in HF, but a plot of the data should be visually examined to gain full understanding of the ventilatory abnormality.

AbstractWe present a novel description of Bezold–Jarisch Reflex (BJR) during cardiopulmonary exercise testing (CPET) in three young female patients with Group 1 pulmonary arterial hypertension (PAH). These three cases presented within 26 months, representing only 0.8% of 11,387 tests on patients with PAH undergoing CPET during this time frame.

Introduction and Hypothesis: In patients with hypertrophic cardiomyopathy (HCM), ventricular tachycardia (VT) is associated with adverse prognosis. Cardiopulmonary exercise testing (CPET) is part of the standard clinical evaluation in HCM. However, limited data are available on the incidence of VT and other adverse events during CPET in HCM. Methods: We reviewed the Mayo Clinic’s Integrated Stress Center Database for CPETs performed on HCM patients between January 2011 and July 2016. Patients were referred for clinical CPET by a physician, and medications were continued for the test. Electronic medical records were reviewed for clinical information and CPET data. Results: A total of 1,208 CPETs were performed on 976 HCM patients during the study period. Most tests were symptom-limited (94.6%), most common symptom was dyspnea (55%). Despite the relatively high number of patients with a history of VT (10.4%) and/or cardiac arrest (1.6%), there was a low rate of adverse events. Non-sustained VT occurred in 6 patients, most frequently during active recovery (3/6), and 2 of these 6 patients had prior history of VT. A 34 year-old female patient experienced sustained VT degenerating into ventricular fibrillation terminated by ICD shock. One patient had syncope during the test but no arrhythmia. Importantly, none of the patients died within 48 hours of the exercise test. Conclusions: In a large cohort of HCM patients, the incidence of VT or other adverse events was a rare finding during symptom-limited CPET.