Permanent sinus dysfunction after pulmonary vein isolation ablation: observations and potential mechanisms.

Although transient sinus arrest has been reported during pulmonary vein isolation (PVI), the long-term impairment of sinus node after PVI has not been described. In this report, we present a case of sinus node dysfunction necessitating a permanent pacemaker, caused during PVI. Clinical data, intracardiac electrograms, and cardiac imaging were incompatible with previous sinus node dysfunction, sinus node artery occlusion, or an ectopic atrial rhythm from the pulmonary veins. Impairment of the neural pathways connecting the ganglionated plexi of the right superior pulmonary veins with the sinus node is a possible underlying mechanism.

Cardiac vagal control in the severity and course of depression: the importance of symptomatic heterogeneity.

BACKGROUND: Impaired cardiac vagal control (CVC), as indexed by respiratory sinus arrhythmia, has been investigated as a risk factor for major depressive disorder (MDD), but prior findings are mixed with respect to whether impaired CVC predicts greater global depression severity and/or a more severe course of disorder. One possible explanation for mixed findings is that CVC abnormalities in MDD are related more closely to specific depression symptoms than to the syndrome as a whole. METHODS: Depression severity (both global and symptom-specific indices) and electrocardiogram measures of resting CVC were obtained from 151 diagnosed MDD participants at intake, before randomization to a novel treatment for depression (acupuncture), and again after 8 and 16 weeks. RESULTS: Resting CVC did not predict global indices of depression in cross-sectional or longitudinal analyses. In symptom-specific analyses, resting CVC was positively related to sad mood and crying and inversely related to middle and late insomnia. Improvement in late insomnia was related to increases in CVC over time. LIMITATIONS: Relationships between CVC and MDD were studied only within the clinical range of severity. Symptom analyses were exploratory and hence did not correct for Type I error. CONCLUSIONS: Resting CVC did not exhibit concurrent or prospective relations with overall depression severity but a few specific symptoms did. Symptomatic heterogeneity across samples may account for mixed findings within the CVC-depression literature.

Respiratory sinus arrhythmia versus neck/trapezius EMG and incentive inspirometry biofeedback for asthma: a pilot study.

This pilot study compared biofeedback to increase respiratory sinus arrhythmia (RSA) with EMG and incentive inspirometry biofeedback in asthmatic adults. A three-group design (Waiting List Control n = 5, RSA biofeedback n = 6, and EMG biofeedback n = 6) was used. Six sessions of training were given in each of the biofeedback groups. In each of three testing sessions, five min. of respiratory resistance and EKG were obtained before and after a 20-min biofeedback session. Additional five-min epochs of data were collected at the beginning and end of the biofeedback period (or, in the control group, self-relaxation). Decreases in respiratory impedance occurred only in the RSA biofeedback group. Traub-Hering-Mayer (THM) waves (.03-.12 Hz) in heart period increased significantly in amplitude during RSA biofeedback. Subjects did not report significantly more relaxation during EMG or RSA biofeedback than during the control condition. However, decreases in pulmonary impedance, across groups, were associated with increases in relaxation. The results are consistent with Vaschillo's theory that RSA biofeedback exercises homeostatic autonomic reflex mechanisms through increasing the amplitude of cardiac oscillations. However, deep breathing during RSA biofeedback is a possible alternate explanation.

Self-regulation of respiratory sinus arrhythmia.

Respiratory sinus arrhythmia (RSA)--the peak-to-peak variations in heart rate caused by respiration--can be used as a noninvasive measure of parasympathetic cardiac control. In the present study four strategies to increase RSA amplitude are investigated: (1) biofeedback of RSA amplitude, (2) biofeedback of RSA amplitude plus respiratory instructions, (3) respiratory biofeedback, and (4) respiratory instructions only. All four procedures produce a significant increase of RSA amplitude from the first physiological control trial compared to baseline. This increase is faster for the groups that received respiratory biofeedback and respiratory instructions only than for the two groups that received biofeedback of RSA amplitude, the increases being equivalent for the four groups in the third session. All subjects of the group that received biofeedback of RSA amplitude only reported respiratory strategies in order to achieve the increase in RSA. Possible clinical implications of these results for parasympathetic cardiac control and cardiovascular disorders are discussed.

[The transesophageal approach to the heart in electrotherapy of trachycardiac arrhythmias. I. Transesophageal electrostimulation procedure]. / Der transöphageale Zugangsweg zum Herzen zur Elektrotherapie tachykarder Rhythmusstörungen. I. Transösophageale Elektrostimulationsverfahren.

Transoesophageal electrostimulation techniques were used in 124 cases of different tachycardiac disturbances of rhythm. By means of highly frequent transoesophageal atrial stimulation we succeeded in transformating into sinus rhythm in 46% of the patients with atrial flutter, in 29% of the cases with atrial tachycardias and in 75% of the patients with av-junctional tachycardias. At least atrial fibrillation (with decrease of the ventricular frequency) could be induced in 48% in pre-existing auricular flutter, in 38% in auricular tachycardias and in 15% in av-junctional atrial (partial success of therapy). Sinus tachycardias, atrial fibrillation and ventricular tachycardias could practically not be influenced by highly frequent transoesophageal atrial stimulation. Moreover, for the first time the techniques of the doubled or coupled atrial stimulation, in 2 cases also ventricular stimulations with higher frequency were tested on transoesophageal way and were introduced into the treatment of tachycardiac disturbances of rhythm. The therapeutic results of transoesophageal electrostimulation techniques seem to be comparable entirely with those of intracardiac stimulations, in which cases the non-invasive and uncomplicated techniques are accessible also to institutions without possibilities of heart catheterization.

Sutureless epicardial pacemaker lead: a satisfactory preliminary experience.

The first pacemaker systems used the epicardial electrode. The transvenous endocardial electrode rapidly supplanted the epicardial electrode since it could be positioned with less morbidity and mortality and was associated with a lower incidence of wire breakage. The long term complication rate of the transvenous electrode had not been inconsequential. The sutureless epicardial electrode combines the greater reliability of the epicardial lead system with the ease of insertion and low morbidity of the endocardial lead system. We have used this electrode in 33 patients. The electrode was positioned using the subxiphoid approach and local anesthesia in most patients. There have been few complications and none that resulted in long term morbidity. There have been no deaths related either to the operative approach or to the pacing system. There has been no instance of lead failure during the follow-up period.