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Query: UMLS:C0037315 (sleep apnea)
 8,000 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Holter recordings of subjects apparently free from cardiovascular disease have demonstrated a moderate sinusal and nodal depression during sleep. This depression does not seem to be sufficient to create overt cardiovascular disorders in apparently healthy subjects, but it may aggravate or even reveal an underlying disorder of rhythm or conduction in elderly people or in patients taking drugs that potentiate its effects. In sleep apnea syndrome prolonged episodes of apnea may produce a paroxysmal, then permanent increase in pulmonary arterial pressure, which may lead to right heart failure. These episodes also increase the pre- and after-load and decrease myocardial contractility, thus facilitating the occurrence of left ventricular failure, potentiated by systemic arterial hypertension, overweight or even coronary disease, all conditions that are often present in these subjects. Arterial hypertension is so frequent in sleep apnea syndrome that some authors advocate a systematic search for the syndrome by Holter recordings before the hypertension is pronounced "essential". All studies confirm the existence of rhythm and conduction disorders directly related to apneic episodes. These disorders decrease or regress after a well-conducted treatment of the sleep apnea syndrome. They are mainly of the "hypokinetic" type, created by depression of sinus activity and conduction pathways. Their frequency, their severity and, in particular, the risk of sudden death they carry seem to have been overestimated, especially since no evidence has ever been produced of a potentially lethal rhythm disorder occurring during sleep apnea. Nevertheless, there is no certainty that these patients are not at risk of sudden death related to their sleep apnea syndrome.
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PMID:[Cardiovascular disorders during sleep]. 214 78

Twelve patients (aged 48 +/- 12 y) with ventricular asystole of >3 s due to complete atrioventricular (AV) block (n = 8), sinoatrial (SA) block or sinus node arrest (n = 3) or both (n = 1) associated with obstructive sleep apnoea underwent invasive electrophysiological evaluation of sinus node function and AV conduction properties before and after administration of atropine (0.02 mg kg-1). Ventricular asystole lasted for 5.9 +/- 2.8 s (range 3.1-13 s). Sinus node function was assessed by measurement of sinus node recovery time, sinoatrial conduction time, and the response of sinus rate to atropine. Parameters of AV-conduction assessment included AH- and HV-intervals, AV- and VA-Wenckebach periods, and effective refractory period of the AV node before and after atropine. Sinus node function was normal in 11 of the 12 study patients and moderately abnormal in 1 patient. AV-nodal function was normal in 8 patients and moderately abnormal in 4 patients. A slightly prolonged HV-interval (59-63 ms) was present in 6 patients. Intra- or infra His block was not observed in any patient. In conclusion, normal or only moderately abnormal electrophysiological findings in patients with sleep apnoea-associated ventricular asystole suggest that a neurally mediated cardioinhibitory reflex may cause ventricular asystole in these patients. This sleep apnoea-triggered 'vasovagal' reflex may unmask pre-existing mild to moderate structural abnormalities of the AV conduction system.
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PMID:Invasive electrophysiological evaluation of patients with sleep apnoea-associated ventricular asystole-methods and preliminary results. 1060 94

In subjects with sinus rhythm, respiration has a profound effect on heart rate variability (HRV) at high frequencies (HF). Because this HF respiratory arrhythmia is lost in atrial fibrillation (AF), it has been assumed that respiration does not influence the ventricular response. However, previous investigations have not considered the possibility that respiration might influence HRV at lower frequencies. We hypothesized that Cheyne-Stokes respiration with central sleep apnea (CSR-CSA) would entrain HRV at very low frequency (VLF) in AF by modulating atrioventricular (AV) nodal refractory period and concealed conduction. Power spectral analysis of R-wave-to-R-wave (R-R) intervals and respiration during sleep were performed in 13 subjects with AF and CSR-CSA. As anticipated, no modulation of HRV was detected at HF during regular breathing. In contrast, VLF HRV was entrained by CSR-CSA [coherence between respiration and HRV of 0.69 (SD 0.22) at VLF during CSR-CSA vs. 0.20 (SD 0.19) at HF during regular breathing, P < 0.001]. Comparison of R-R intervals during CSR-CSA demonstrated a shorter AV node refractory period during hyperpnea than apnea [minimum R-R of 684 (SD 126) vs. 735 ms (SD 147), P < 0.001] and a lesser degree of concealed conduction [scatter of 178 (SD 56) vs. 246 ms (SD 72), P = 0.001]. We conclude that CSR-CSA entrains the ventricular response to AF, even in the absence of HF respiratory arrhythmia, by inducing rhythmic oscillations in AV node refractoriness and the degree of concealed conduction that may be a function of autonomic modulation of the AV node.
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PMID:Influence of Cheyne-Stokes respiration on ventricular response to atrial fibrillation in heart failure. 1599 46

While the left bundle branch block frequently reflects underlying cardiac disease, conductive disorders occurring at three levels (sinus node, atrioventricular node, and branches of the bundle of His), are usually part of the aging heart. In addition, AV nodal block and sinus node dysfunction are readily compounded with drugs, often indispensable (beta-blockers, calcium-blockers, digoxin, antiarrhythmic), and very common among the elderly. Indications for permanent pacing are accurately described and come in four classes: I, recommended (mandatory) - IIa, raisonable - IIb, possible - III, contraindicated. In 2009, 24H ECG Holter and electrophysiological study are generally disappointing in the positive diagnosis of syncope, so the clinical characteristics of syncope are essential in the decision of device implantation. Indeed, in the absence of ECG recorded at the time of the syncope, the diagnosis of BAV or BSA cannot be certain, and on the contrary, vague symptoms should not be attributed to a patent bradycardia of sinus or AV block origin without any precaution. Finally, the relationship between sinus dysfunction and carotid sinus syndrome remain poorly understood, dysautonomia is common among the elderly, and the existence of conduction disorders associated with syndrome of sleep apnea should not be ignored.
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PMID:[Cardiac conduction disorders in the elderly]. 2005 60

B-cell small lymphocytic lymphoma typically involves nodal or extranodal tissues as a diffuse proliferation with proliferation centers (pseudofollicules) obliterating normal architecture. But there are unusual patterns of involvement including interfollicular pattern that can be difficult to recognize histologically and probably represent partial or early involvement by neoplasm. Tonsillar lymphoma usually presents either as a unilaterally enlarged palatine tonsil or as an ulcerative and fungating lesion over the tonsillar area. Most lymphomas that involve the tonsil are diffuse large B cell lymphomas and primary low-grade lymphomas are exceptional. We present a primary B-cell small lymphocytic lymphoma affecting palatine tonsils with interfollicular pattern in a 54 year-old man that clinically presented with symmetric / bilateral tonsillar enlargement and sleep apnea.
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PMID:[Bilateral tonsillar hypertrophy as the first manifestation of B cell-small lymphocytic lymphoma with interfolicular pattern]. 2069 11