Evidence for contact calls in fish: conspecific vocalisations and ambient soundscape influence group cohesion in a nocturnal species.

Soundscapes provide a new tool for the study of fish communities. Bigeyes (Pempheris adspersa) are nocturnal planktivorous reef fish, feed in loose shoals and are soniferous. These vocalisations have been suggested to be contact calls to maintain group cohesion, however direct evidence for this is absent, despite the fact that contact calls are well documented for many other vertebrates, including marine mammals. For fish, direct evidence for group cohesion signals is restricted to the use of visual and hydrodynamic cues. In support of adding vocalisation as a contributing cue, our laboratory experiments show that bigeyes significantly increased group cohesion when exposed to recordings of ambient reef sound at higher sound levels while also decreasing vocalisations. These patterns of behaviour are consistent with acoustic masking. When exposed to playback of conspecific vocalisations, the group cohesion and vocalisation rates of bigeyes both significantly increased. These results provide the first direct experimental support for the hypotheses that vocalisations are used as contact calls to maintain group cohesion in fishes, making fish the evolutionarily oldest vertebrate group in which this phenomenon has been observed, and adding a new dimension to the interpretation of nocturnal reef soundscapes.

Left ventricular assist device as a bridge to recovery in a young woman admitted with peripartum cardiomyopathy.

Left ventricular assist devices (LVAD) are an effective therapeutic option for end-stage heart failure patients as a bridge to cardiac transplantation in those who deteriorate despite maximal therapy and when a donor heart is not ready available. In some patients, cardiac recovery has been reported while supported by an LVAD. In this case report, we describe a 29-year-old female who was admitted to our centre because of peripartum cardiomyopathy (PPCM). Despite intensive treatment with intravenous inotropes and intra-aortic balloon counter-pulsation she had a persisting low cardiac index and an LVAD was implanted. In the months following implantation the left ventricular systolic function improved and the left ventricular dimensions normalised. Eventually the LVAD could be ex-planted nine months after implantation. At this moment, three years after explantation, echo-cardiography shows a normal-sized left ventricle and almost completely recovered systolic function. (Neth Heart J 2008;16:426-8).

[Unexplained right ventricle dilatation clarified by a cardiac contusion many years ago]. / Onbegrepen rechterventrikeldilatatie verklaard door een contusio cordis vele jaren daarvoor.

In a 52-year-old man with new onset atrial fibrillation, transthoracic echocardiography showed an isolated, considerably dilated right ventricle. Frequent causes of right ventricular dilatation were ruled out. The image-forming investigation showed an isolated dilation of the ventral part of the heart, which, in combination with a blunt chest trauma 30 years previously, led to a previous cardiac contusion being suspected. In accordance with this hypothesis myocardial scintigraphy showed asymmetric hypertrophy of the right ventricular wall, which is consistent with the remodeling that occurs in response to injured cardiac tissue. After electrical cardioversion sinus rhythm was obtained; the patient remained symptom free.

Decisions to terminate resuscitation. Resuscitation Committee.

To gain more insight into decision making around the termination of resuscitation (CPR), we studied factors which influenced the time before discontinuing resuscitation, and the criteria on which those decisions were based. These criteria were compared with those of the European Resuscitation Council (ERC) and the American Heart Association (AHA). For this study, we reviewed the audiotapes of resuscitation attempts in a hospital. A total of 36 attempts were studied, involving 27 men and nine women, mean (S.D.) age 64 (18) years. A total of 19 patients received resuscitation on general wards, and 17 in the emergency room after an out-of-hospital circulatory arrest. The median interval time (range) from start to termination was 33 min (8-81 min). Results from multiple linear regression showed that a delay greater than 5 min in first advanced life support measures, drawing a sample for biochemical analysis, and the patient's response shown by return of spontaneous circulation were independently associated with the time of terminating resuscitation. The team used a number of criteria which can be found in the guidelines of the ERC and the AHA, but also used additional criteria. The ERC and the AHA criteria were not sufficient to cover all termination decisions. We conclude that the point in time to terminate resuscitation is not always rationally chosen. Updating of the current guidelines for terminating resuscitation and training resuscitation teams to use these guidelines is recommended.