Comparison of a party balloon inflation manoeuvre and goal-directed valsalva manoeuvre for provoking leftventricular outflow tract obstruction

Background Left ventricular outflow tract (LVOT) obstruction is a key feature of hypertrophicobstructive cardiomyopathy (HOCM). The Valsalva manoeuvre (VM) is a simple, non-invasive, and standardprovocative technique. However, prior studies on goal-directed VM (GDVM) in HOCM using a syringe barrel with amanometer to maintain intraoral pressure >40 mmHg suggested that this approach may reclassify HOCM casescompared to VM (1, 2). Consequently, we developed a party balloon inflation manoeuvre (PBIM) which offers simplicity and cost-effectiveness, and provides clear visual feedback for both test staff and patient and we reported clinical cases where the PBIM proved more effective than the conventional VM in diagnosing HOCM (3).We aimed to evaluate the PBIM as an alternative to GDVM for diagnosing HOCM by comparing their haemodynamic effect. Purpose This study aimed to evaluate PBIM as an alternative to GDVM for enhancing LVOT obstruction by comparing the haemodynamic effect in healthy volunteers. Methods In this single-centre pilot study, twelve healthy adult healthcare worker volunteers who were physicians(median age 32 years, 100% male) were enrolled. For the GDVM protocol, participants performed the manoeuvre by blowing into a syringe barrel connected to a manometer via rubber tubing (Figure 1A) and maintaining an intraoral pressure exceeding 40 mmHg for more than 10 seconds (1, 2). In PBIM protocol, based on our benchmark test (Figure 1B), balloon inflation was maintained for at least 5 seconds using designated balloonsizes, with the small balloon (SB) and large balloon (LB) reaching peak pressures at diameters of 5 cm and 7 cm,respectively. The primary endpoints were the left ventricular end-diastolic diameter (LVDd) and volume (LVEDV),measured using three-dimensional transthoracic echocardiography during the manoeuvre. Results Both PBIM protocols and GDVM resulted in a reduction in LVEDV compared with the resting state (p <0.01 for SB 5cm and p < 0.05 for LB 7 cm and GDVM). There were no significant differences among PBIM protocols and GDVM (Figure 2 A). Similarly, LVDd decreased in all PBIM protocols and GDVM compared to restingstate (p < 0.01) and there were no significant differences among PBIM protocols and GDVM (Figure 2 B). Conclusions PBIM effectively provoked the haemodynamic changes resulted in a comparable reduction in LV volume similar to those induced by GDVM. The findings suggest that PBIM, using simple tool, may be a reliableand practical alternative to GDVM for diagnosis in patients of HOCM.