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Background Dynamic LV outflow tract (OT) systolic pressure gradient (SPG) and dysfunction of the mitral valve (MV) are classical features of hypertrophic obstructive cardiomyopathy (HOCM).The physiological substantiation of the SPG and mitral regurgitation origion in HOCM is insufficient. The present study exemines if LV OT obstruction and mitral regurgitation in HOCM can be conditioned by LV activation asynchrony caused by LV excitation sequence disturbances. Methods 55 consequtive HOCM pts (mean age 31.7±3.2 yrs) were evaluated by M-mode, two dimentional and Doppler echocardiography with SPG determination, mitral regurgitation assesment, and short distance (h, cm) between interventricular septum (IVS) and MV anterior leaflet in systole measurement; by cardiac catheterization with direct LV OT SPG measurement and by LV endocardial mapping in relation to His potential registered in the AV node region. We compared the LV apex (LVA) His-V interval with the same for the hypertrophied part of IVS and calculated the difference in ms (δt) between the His-VLVA and the His-VLV OT. The the “–” sign before the δ t index showing the LV apex delay as compared to its OT activation. Results The linear regression analyses revealed: 1) negative relations between h (distance between IVS and anterior MV leaflet in systole and SPG on LVOT (r=−0, 4, p<0, 001), 2) negative relation between the δ t index and SPG magnitude (r=−0.32, p<0.001), and 3) positive relation between δ t and h, (r =0.3, p =0.001). Conclusion The LV outflow tract systolic pressure gradient and mitral regurgitation in HOCM are conditioned by the LV activation asynchrony caused by LV apex and papillary muscles activation delay relatively to the hypertrophied part of IVS. [ABSTRACT FROM PUBLISHER]

Background The effectiveness of DDD pacing in the case of hypertrophic obstructive cardiomyopathy (HOCM) depends on the optimal AV delay (AVD) programming. There are no criterions of appropriate AVD calculation. We hypothesized that the optimal AVD may depend on the interapex preexcitation time (IAPT). The present study exemines if DDD pacing efficathy is depends upon an IAPT magnitude. Methods IAPT measurement was performed in 21 HOCM patients with LV OT SPG>30 mm Hg. IAPT was determined with the help of step-by-step AVD shortening with RVA pacing from the sensing of RVA's own excitation by pacemaker (initial AVD) up to the moment of shortening of AV interval on the LVA catheter. That is the IAPT is the necessary RVA pre-excitation period needed to achieve LVA pre-excitation. Outflow tract systolic pressure gradient (SPG) was assesed by Echocardiography. Results The maximum SPG reduction (ranging from 30% to 100% of initial values) occurred with AVD shortening by 80-120 ms from initial AVD and persisted up to the moment of mitral valve wedging. The onset of this period gradient decrease coincided with the IAPT end phase, which appeared to be a stabile value of 100-120 ms in adults and 80-100 ms in children. The efficient DDD pacing therapy of HOCM was possible only if the IAPT was smaller than the AV interval of RVA and can launch LVA pre-excitation after the left atrial systole providing time for its complete contraction. Conclusion The clarification of IAPT enables reliable AVD programming in HOCM patients. All you need is to determine the real AV conductance time with atrium faster-thansinus-rhythm pacing (DDD-regime) and with atrial excitation detection (VDD-regime) and to subtract the time of interapical preexcitation. To secure a reliable ALV preexcitation on various systolic frequencies one needs to correctly program the physiological frequencydependent AV interval linear shortening. [ABSTRACT FROM PUBLISHER]

Guapinannus Wygodzinsky, 1951 (Hemiptera: Schizopteridae) was described based on a single female specimen from Costa Rica. Some additional specimens representing this genus have since become available and were incorporated into a comparative male genitalic study across Dipsocoromorpha and into combined molecular and morphological hypotheses of the infraorder. However, the species-level diversity of Guapinannus has remained unexplored and undocumented. Based on examination of 264 specimens from central and South America, we here revise the taxonomy of Guapinannus, describing 19 species as new (Guapinannus anaticulus, sp. n.; Guapinannus artus, sp. n.; Guapinannus auriculus, sp. n.; Guapinannus castigatus, sp. n.; Guapinannus clava, sp. n.; Guapinannus dispar, sp. n.; Guapinannus falcis, sp. n.; Guapinannus graziae, sp. n.; Guapinannus minutus, sp. n.; Guapinannus orbiculatus, sp. n.; Guapinannus plurilobus, sp. n.; Guapinannus policis, sp. n.; Guapinannus robustus, sp. n.; Guapinannus sinuosus, sp. n.; Guapinannus tatumbia, sp. n.; Guapinannus tenuis, sp. n.; Guapinannus tergus, sp. n.; Guapinannus trilobus, sp. n.; Guapinannus uncus, sp. n.). In addition, we provide photos of the female holotype of Guapinannus bierigi Wygodzinsky, 1951, SEM documentation for Guapinannus clava, sp. n., habitus photos and a map for all species, and line drawings of male genitalic features for all species for which males are known.