ObjectiveThe Valsalva maneuver is the most sensitive provocative maneuver for patent foramen ovale detection. However, nearly half of patients are unable to perform the Valsalva maneuver well. The aim of this study was to investigate the mechanism of action of calf muscle pump tensing (TENSE) as a novel patent foramen ovale (PFO) provocative maneuver and to evaluate the diagnostic value for PFO and the effect on right-to-left shunt volume compared with the Valsalva maneuver.MethodsThis study prospectively investigated 171 patients who were highly suspected to have PFO clinically. Five patients with atrial septal defects newly diagnosed on transesophageal echocardiography (TEE) were excluded. 166 patients were injected with agitated saline under three provocative maneuvers: Valsalva maneuver, TENSE, and Valsalva + TENSE combined maneuver. The patients were divided into the effective Valsalva group (n = 93) and ineffective Valsalva group (n = 73) according to whether they could perform an effective Valsalva maneuver. TENSE consisted of the straightening of both lower limbs, and when the right atrium was filled with microbubbles, the patient performed instantaneous ankle dorsiflexion movements while maintaining dorsiflexion for 3–5 s.ResultsOverall, the PFO detection rate of the Valsalva + TENSE combined maneuver (78 [50.1%]) was significantly higher than that of the Valsalva maneuver (51 [30.7%]) and TENSE maneuver (57 [34.3%]) (P < 0.001). In the patients who were able to perform an effective Valsalva maneuver, the PFO detection rate by TENSE was not significantly different from that by the Valsalva maneuver (Valsalva 37/93 [39.8%] vs. TENSE 31/93 [33.3%], P > 0.05), while for the patients who performed an ineffective Valsalva maneuver, the PFO detection rate by the TENSE maneuver was higher than that by the Valsalva maneuver (TENSE 26/73 [35.6%] vs. Valsalva14/73[19.2%], P = 0.017).ConclusionTENSE is a simple and effective provocative maneuver in the diagnosis of PFO using TEE and can assist the Valsalva maneuver. For patients who cannot perform an effective Valsalva maneuver, TENSE can be an alternative to the Valsalva maneuver to some extent.

ObjectivePulmonary right-to-left shunt (P-RLS) and patent foramen ovale right-to-left shunt (PFO-RLS) often appear in combination, and there are often differences and connections between them. Intrapulmonary arteriovenous anastomoses (IPAVAs), as part of P-RLS, are often overlooked because there are no technologies to detect and identify them. This study aimed to further clarify the incidence and characteristics of P-RLS with the help of contrast transesophageal echocardiography (c-TEE) and contrast transthoracic echocardiography (c-TTE), providing a reference for clinically relevant research and patent foramen ovale (PFO) management disposal decisions.MethodsWe retrospectively investigated 414 subjects who came to our hospital for c-TEE from October 2021 to July 2022, and all subjects completed c-TTE simultaneously. 7 Patients who were newly diagnosed with an atrial septal defect were excluded. Eventually, 407 patients were included in this study. Among them, 157 patients with PFO (58 patients were treated with PFO closure subsequently) and 250 patients without PFO confirmed by c-TEE were finally enrolled. In the process, we observed and analysed the presence of P-RLS.ResultsA total of 407 patients were included in the final analysis and divided into PFO group (N = 157) and non-PFO group (N = 250) according to the results of c-TEE. Whether at rest or after Valsalva maneuver, the incidence of P-RLS was significantly higher under c-TEE than under c-TTE in the two groups (P < 0.001). For both c-TTE and c-TEE, the incidence of P-RLS was slightly higher after Valsalva maneuver than at rest, but the difference was not significant (c-TTE: rest vs. Valsalva maneuver, P = 0.214; c-TEE: rest vs. Valsalva maneuver, P = 0.076). The Valsalva maneuver increased the incidence of P-RLS in the group without PFO, which was more significant in c-TEE (c-TTE: rest vs. Valsalva maneuver, P = 0.591; c-TEE: rest vs. Valsalva maneuver, P = 0.008). In both groups, the P-RLS semiquantitative grading was statistical significance under different states and examinations (P < 0.001).ConclusionThe vast majority of P-RLS are grade 1–2 and are derived from physiological IPAVAs. Even so, attention should be given to the differentiation between P-RLS and PFO-RLS. c-TEE is an effective method to detect P-RLS; however, the recruitments of c-TEE and Valsalva maneuver to P-RLS should be noted.