Comparison of procedural efficacy and biophysical parameters between two competing cryoballoon technologies for pulmonary vein isolation: Insights from an initial multicenter experience

Introduction: Recently a novel cryoballoon system (POLARx, Boston Scientific) became available for the treatment of atrial fibrillation. This cryoballoon is comparable with Arctic Front Advance Pro (AFA-Pro, Medtronic), however, it maintains a constant balloon pressure. We compared the procedural efficacy and biophysical characteristics of both systems. Methods: One hundred and ten consecutive patients who underwent first-time cryoballoon ablation (POLARx: n = 57; AFA-Pro: n = 53) were included in this prospective cohort study. Results: Acute isolation was achieved in 99.8% of all pulmonary veins (POLARx: 99.5% vs. AFA-Pro: 100%, p = 1.00). Total procedure time (81 vs. 67 min, p <.001) and balloon in body time (51 vs. 35 min, p <.001) were longer with POLARx. After a learning curve, these times were similar. Cryoablation with POLARx was associated with shorter time to balloon temperature −30°C (27 vs. 31 s, p <.001) and −40°C (32 vs. 54 s, p <.001), lower balloon nadir temperature (−55°C vs. −47°C, p <.001), and longer thawing time till 0°C (16 vs. 9 s, p <.001). There were no differences in time-to-isolation (TTI; POLARx: 45 s vs. AFA-Pro 43 s, p =.441), however, POLARx was associated with a lower balloon temperature at TTI (−46°C vs. −37°C, p <.001). Factors associated with acute isolation differed between groups. The incidence of phrenic nerve palsy was comparable (POLARx: 3.5% vs. AFA-Pro: 3.7%). Conclusion: The novel cryoballoon is comparable to AFA-Pro and requires only a short learning curve to get used to the slightly different handling. It was associated with faster cooling rates and lower

Cardiac magnetic resonance imaging during pulmonary hyperinflation in apnea divers

Apnea divers hyperinflate the lung by taking a deep breath followed by glossopharyngeal insufflation. The maneuver can lead to symptomatic arterial hypotension. We tested the hypotheses that glossopharyngeal insufflation interferes with cardiac function further reducing cardiac output (CO) using cardiac magnetic resonance imaging (MRI) to fully sample both cardiac chambers

Comparison of procedural efficacy and biophysical parameters between two competing cryoballoon technologies for pulmonary vein isolation: Insights from an initial multicenter experience

Introduction: Recently a novel cryoballoon system (POLARx, Boston Scientific) became available for the treatment of atrial fibrillation. This cryoballoon is comparable with Arctic Front Advance Pro (AFA-Pro, Medtronic), however, it maintains a constant balloon pressure. We compared the procedural efficacy and biophysical characteristics of both systems. Methods: One hundred and ten consecutive patients who underwent first-time cryoballoon ablation (POLARx: n = 57; AFA-Pro: n = 53) were included in this prospective cohort study. Results: Acute isolation was achieved in 99.8% of all pulmonary veins (POLARx: 99.5% vs. AFA-Pro: 100%, p = 1.00). Total procedure time (81 vs. 67 min, p <.001) and balloon in body time (51 vs. 35 min, p <.001) were longer with POLARx. After a learning curve, these times were similar. Cryoablation with POLARx was associated with shorter time to balloon temperature −30°C (27 vs. 31 s, p <.001) and −40°C (32 vs. 54 s, p <.001), lower balloon nadir temperature (−55°C vs. −47°C, p <.001), and longer thawing time till 0°C (16 vs. 9 s, p <.001). There were no differences in time-to-isolation (TTI; POLARx: 45 s vs. AFA-Pro 43 s, p =.441), however, POLARx was associated with a lower balloon temperature at TTI (−46°C vs. −37°C, p <.001). Factors associated with acute isolation differed between groups. The incidence of phrenic nerve palsy was comparable (POLARx: 3.5% vs. AFA-Pro: 3.7%). Conclusion: The novel cryoballoon is comparable to AFA-Pro and requires only a short learning curve to get used to the slightly different handling. It was associated with faster cooling rates and lower balloon temperatures but TTI was similar to AFA-Pro

Glossopharyngeal insufflation induces cardioinhibitory syncope in apnea divers

Apnea divers increase intrathoracic pressure voluntarily by taking a deep breath followed by glossopharyngeal insufflation. Because apnea divers sometimes experience hypotension and syncope during the maneuver, they may serve as a model to study the mechanisms of syncope. We recorded changes in hemodynamics and sympathetic vasomotor tone with microneurography during breath holding with glossopharyngeal insufflation. Five men became hypotensive and fainted during breath holding with glossopharyngeal insufflation within the first minute. In four divers, heart rate dropped suddenly to a minimum of 38 +/- 4 beats/min. Therefore, cardioinhibitory syncope was more common than low cardiac output syncope

Cardiovascular regulation during apnea in elite divers

Involuntary apnea during sleep elicits sustained arterial hypertension through sympathetic activation; however, little is known about voluntary apnea, particularly in elite athletes. Their physiological adjustments are largely unknown. We measured blood pressure, heart rate, hemoglobin oxygen saturation, muscle sympathetic nerve activity, and vascular resistance before and during maximal end-inspiratory breath holds in 20 elite divers and in 15 matched control subjects. At baseline, arterial pressure and heart rate were similar in both groups. Maximal apnea time was longer in divers (1.7+/-0.4 versus 3.9+/-1.1 minutes; P5-fold greater muscle sympathetic nerve activity increase (P<0.01) with a massively increased pressor response compared with control subjects (9+/-5 versus 32+/-15 mm Hg; P<0.001). Vascular resistance increased in both groups, but more so in divers (79+/-46% versus 140+/-82%; P<0.01). Heart rate did not change in either group. The rise in muscle sympathetic nerve activity correlated with oxygen desaturation (r(2)=0.26; P<0.01) and with the increase in mean arterial pressure (r(2)=0.40; P<0.0001). In elite divers, breath holds for several minutes result in an excessive chemoreflex activation of sympathetic vasoconstrictor activity. Extensive sympathetically mediated peripheral vasoconstriction may help to maintain adequate oxygen supply to vital organs under asphyxic conditions that untrained subjects are not able to tolerate voluntarily. Our results are relevant to conditions featuring periodic apnea