Recurrent sudden depression of cardiac functions during obstructive apneas
may lead to cardiac structural remodeling as well as cardiac muscle weakness, contractile dysfunction, myocardial ischemia, ventricular dilation and consequently, cause HF at long term (52).
during sleep in patients with seasonal allergic rhinitis.
Obstructive apnea that is characterized by an initial central component followed by a collapse of the upper airway at the onset of respiratory effort has been termed mixed apnea.
An obstructive apnea results in an arousal or microarousal, with a return to the awake pattern of homeostasis.
Respiratory patterns reflecting intercostal/abdominal changes, summed in a third channel, identify obstructive apnea
Different heart rate patterns in obstructive apneas
during NREM sleep.
Since then," he said, "patients are substantially fatter, and we think there are more obstructive apneas
in heart failure patients than there used to be.
8) Interestingly, the hypoxia that occurs during these apneic spells alone does not explain blood pressure elevations after obstructive apneas, (6) but is only one of the factors that, when added together, lead to hypertension in patients with OSA.
60) These findings emphasize that the diseased myocardium is more susceptible to the adverse effects of obstructive apneas than is the normal myocardium.
Cardiovascular mechanisms, such as increased blood pressure, heart rate and daytime muscle sympathetic nerve activity, which all are involved in the poor prognosis of HF patients were found to be reduced with CPAP In this context, using cardiac C-11 acetate positron emission tomography in HF patients with OSA, obstructive apneas
were shown to depress cardiac function acutely while CPAP treatment was associated with improved cardiac function (50).
And if the sleep technologist raises either expiratory or inspiratory pressures in response to continuing obstructive apneas
, hypopneas or snoring, both the frequency and length of the central events seem to increase.
He experienced 117 obstructive apneas
and 28 hypopneas, and his combined respiratory index was 24 events per hour.