Circadian patterns in the onset of cardiogenic acute pulmonary edema

Circadian variation of cardiogenic pulmonary oedema

INTRODUCTION

Circadian variation of in-hospital acute cardiogenic pulmonary oedema (CPE) with the highest occurrence in the early morning has been reported repeatedly. However, no study evaluating circadian variation of CPE in the field has been published. Therefore, we decided to evaluate the circadian variation of CPE in the Central Bohemian Region of the Czech Republic in the patients treated by regional emergency medical service (EMS) and analyse its association with baseline blood pressure in the field.

METHODS

We extracted all dispatches to CPE cases from EMS database for the period from 1.11.2008 to 30.6.2014 and analysed for circadian variation. We identified the patients presenting with CPE coupled with arterial hypertension (systolic blood pressure >140mmHg) and hypotension (systolic blood pressure <90mmHg) and compared the subgroups (both subgroups include 2744 subjects).

RESULTS

In 4747 episodes of CPE, maximal occurrence was detected in the ninth hour in the morning, representing 7.7% of all CPE episodes (p<0.05). While CPE with hypertension (2463 subjects) reached maximal occurrence also in the ninth hour (7.4% of all cases, p<0.05), CPE with hypotension (281 patients) was most frequent in the fourteenth hour (8.6% of all cases, p<0.05).

CONCLUSION

The highest occurrence of CPE was observed in the ninth hour in the morning in our study. Moreover, differences in circadian variation between CPE with hypertension and hypotension were identified. Knowledge of these patterns may have an impact on the logistic of prehospital emergency care and on preventive measures in the patients who have previously undergone CPE.

Diurnal and twenty-four hour patterning of human diseases: cardiac, vascular, and respiratory diseases, conditions, and syndromes

Various medical conditions, disorders, and syndromes exhibit predictable-in-time diurnal and 24 h patterning in the signs, symptoms, and grave nonfatal and fatal events, e.g., respiratory ones of viral and allergic rhinorrhea, reversible (asthma) and non-reversible (bronchitis and emphysema) chronic obstructive pulmonary disease, cystic fibrosis, high altitude pulmonary edema, and decompression sickness; cardiac ones of atrial premature beats and tachycardia, paroxysmal atrial fibrillation, 3rd degree atrial-ventricular block, paroxysmal supraventricular tachycardia, ventricular premature beats, ventricular tachyarrhythmia, symptomatic and non-symptomatic angina pectoris, Prinzmetal vasospastic variant angina, acute (non-fatal and fatal) incidents of myocardial infarction, sudden cardiac arrest, in-bed sudden death syndrome of type-1 diabetes, acute cardiogenic pulmonary edema, and heart failure; vascular and circulatory system ones of hypertension, acute orthostatic postprandial, micturition, and defecation hypotension/syncope, intermittent claudication, venous insufficiency, standing occupation leg edema, arterial and venous branch occlusion of the eye, menopausal hot flash, sickle cell syndrome, abdominal, aortic, and thoracic dissections, pulmonary thromboembolism, and deep venous thrombosis, and cerebrovascular transient ischemic attack and hemorrhagic and ischemic stroke. Knowledge of these temporal patterns not only helps guide patient care but research of their underlying endogenous mechanisms, i.e., circadian and others, and external triggers plus informs the development and application of effective chronopreventive and chronotherapeutic strategies.

Circadian study of decompression sickness symptoms and response-associated variables in rats

In order to study circadian rhythms and decompression sickness (DCS), we determined: 1) the baseline circadian time structure in noncompressed rats of potential response variables to compression/decompression (C/D), and 2) whether rats subjected to C/D display a circadian time-dependent difference in inflammatory response intensity and biological tolerance. Subgroups of male rats, standardized to a 12 h light/12 h dark schedule, were evaluated every 4 h over 24 h after they were either compressed to 683 kPa (group E) or remained at sea level (group C). During 60 min recovery, evaluation included gross DCS symptoms and pulmonary edema in all E rats, and cell counts, nitric oxide, protein, thromboxane B(2,) and leukotriene E(4) levels in survivors. Chi-square, ANOVA, and 24 h cosinor analyses were used to test for time-of-day effects. C/D exposures near the end of dark/activity or during light/resting were generally better tolerated, with lowest signs of DCS symptoms and lowest responses by most of the variables monitored. More deaths were observed in the first half of the dark/activity span. Of the 16 subsets of inflammatory-associated variables, overall increases were observed in 13 and decreases in 2. Significant or borderline significant circadian time effects were found in 14 variables in group C, 12 variables in group E, and 13 variables in response (E%C). Thus, nearly all baseline indices of DCS demonstrated circadian time-dependencies in the sea-level exposed control rats (group C), and nearly all were modified by the circadian time of C/D. Such time-of-day effects of DCS are potentially relevant to the operational concerns of occupations involving decompression exposures and the investigation of prevention and treatment intervention strategies of DCS.

Circadian variation in onset of acute cardiogenic pulmonary edema is independent of patients' features and underlying pathophysiological causes

BACKGROUND

The present study aimed to confirm the existence of a circadian pattern in the onset of acute pulmonary edema (APE) and to verify whether sex, age, preexisting diseases, and clinical causes determining the event may influence it.

SUBJECTS AND METHODS

The study considered all consecutive cases of APE observed at the St. Anna General Hospital of Ferrara, Italy, during a 7-year period from January 1, 1992, to December 31, 1998. The sample population was divided into subgroups by sex, age (<75 and > or =75 years), presence or absence of diabetes and hypertension, clinical causes determining the event (i.e., acute myocardial infarction (AMI), pulmonary embolism, arrhythmias). The most important associated or concomitant diseases were also considered (i.e., coronary heart disease and angina, previous myocardial infarction, chronic cardiac failure, dilatative cardiopathy, chronic atrial fibrillation, valvular disease, chronic obstructive pulmonary disease, chronic cor pulmonale, malignancy, chronic renal failure). Time of symptom onset of each event was recorded accurately, then tabulated into 24 increments of 1h (e.g., 06:00 to 06:59 was reported as 6 A.M.). For statistical chronobiological analysis, partial Fourier series were used.

RESULTS

During the 7-year period, 1321 consecutive cases of APE in 1014 different subjects were observed. The majority of events occurred at night, and statistical analysis showed a 24h rhythmicity both in the total sample population and in all considered subgroups, with the only exception being patients with pulmonary embolism and arrhythmias, for which the small number of cases made the study of rhythms in APE impossible.

CONCLUSIONS

The nighttime preference in the occurrence of APE appears to be quite independent of all demographic features or underlying pathophysiological causes.