Daily distribution of episodes of acute cardiogenic pulmonary edema

The Circadian Biology of Heart Failure

Driven by autonomous molecular clocks that are synchronized by a master pacemaker in the suprachiasmatic nucleus, cardiac physiology fluctuates in diurnal rhythms that can be partly or entirely circadian. Cardiac contractility, metabolism, and electrophysiology, all have diurnal rhythms, as does the neurohumoral control of cardiac and kidney function. In this review, we discuss the evidence that circadian biology regulates cardiac function, how molecular clocks may relate to the pathogenesis of heart failure, and how chronotherapeutics might be applied in heart failure. Disrupting molecular clocks can lead to heart failure in animal models, and the myocardial response to injury seems to be conditioned by the time of day. Human studies are consistent with these findings, and they implicate the clock and circadian rhythms in the pathogenesis of heart failure. Certain circadian rhythms are maintained in patients with heart failure, a factor that can guide optimal timing of therapy. Pharmacologic and nonpharmacologic manipulation of circadian rhythms and molecular clocks show promise in the prevention and treatment of heart failure.

Mid-regional pro-adrenomedullin outperforms N-terminal pro-B-type natriuretic peptide for the diagnosis of acute heart failure in the presence of atrial fibrillation

AIMS

The performance of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in diagnosing acute decompensated heart failure (ADHF) among patients presenting with breathlessness is markedly impaired in the presence of atrial fibrillation (AF). We evaluated the diagnostic performance of mid-regional pro-adrenomedullin (MR-proADM) and cardiac troponin T as possible alternative markers for discrimination of ADHF in this setting.

METHODS AND RESULTS

Breathless patients (n = 1107) were prospectively and contemporaneously recruited in emergency departments in Singapore and New Zealand. The diagnoses of ADHF and presence of AF were adjudicated by two clinician specialists, blinded to MR-proADM, NT-proBNP and high-sensitivity cardiac troponin T (hs-cTnT) results. MR-proADM exhibited strong discrimination of ADHF with little change in performance irrespective of the presence of AF (area under the curve 0.83 in non-AF vs. 0.76 in AF) compared to NT-proBNP (0.91 vs. 0.71) and hs-cTnT (0.83 vs. 0.62), respectively. The accuracy of MR-proADM (73.3%) for diagnosing ADHF among patients with AF was superior to both NT-proBNP (61.6%) and hs-cTnT (64.6%). The superior performance of MR-proADM remained apparent when data from Singapore and New Zealand were analysed separately.

CONCLUSION

In the presence of AF, MR-proADM showed greater discrimination and accuracy, and less impairment in performance compared to that in non-AF cases, for the diagnosis of ADHF, compared to the guideline-endorsed NT-proBNP.

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.

Monthly, weekly, and daily patterns in the incidence of congestive heart failure

OBJECTIVE

To determine whether there are patterns in the incidence of emergency department (ED) visits for congestive heart failure (CHF) by month of the year, day of the week, or hour of the day.

METHODS

This was a retrospective analysis of a computerized billing database of ED visits, involving seven northern New Jersey hospitals EDS: Consecutive patients seen by emergency physicians over an 11-year period (January 1, 1988--December 31, 1998) were included. Chi-square tests were used to evaluate for significant differences (p < 0.05).

RESULTS

There were a total of 2,370,233 patients in the database, of whom 26,224 had a primary ED diagnosis of CHF. The chi-square test rejected uniformity for month of the year, for day of the week, and for hour of the day (p < 0.0001). Visits for CHF were increased in the winter months. Compared with the average of the other months, December was the highest (14.3% above, p < 0.0001) and August was the lowest (15.5% below, p < 0.0001). There was also a day-of-the-week variation. Compared with the average of the other days, Monday was the highest (14.5% above, p < 0.0001) and Saturday was the lowest (9.6% below, p < 0.0001). There was also an hour-of-the-day pattern, with a rapid rise after 8 AM and a downtrend after 3 PM.

CONCLUSIONS

These data revealed a higher incidence of ED visits for CHF in the winter months, on Mondays, and during the hours of 8 AM to 3 PM. In comparison with previous studies, these data revealed a similar pattern by month of the year and a different pattern by hour of the day.

Ambulatory blood pressure in heart failure

Ambulatory blood-pressure monitoring (ABPM) is accepted in the evaluation and management of hypertension. The use of ABPM in heart failure has received considerably less attention. Many patients with advanced heart failure experience disabling fatigue, orthostatic dizziness and symptoms of coronary and cerebrovascular insufficiency that may relate to periods of hypotension. These may be exacerbated by vasodilator drug therapy and may be difficult to evaluate by casual clinic recordings. ABPM in heart failure may help in the following: (i) evaluating time-dependent pharmacodynamic drug effects, such as peak and end-of-dose phenomena, tolerance and rebound; (ii) titrating ACE inhibitors and other drugs to highest-tolerated doses; and (iii) correlating circadian blood-pressure profiles with symptoms, quality of life, severity of heart failure, progression of ventricular and renal dysfunction, risks of stroke and myocardial infarction, and life expectancy. Devices for ABPM have been beset by problems of inaccuracy and unreliability. Standards for their manufacture and sale (including bench tests of accuracy against sphygmomanometry and intra-arterial recordings, and field tests of reliability) have been devised independently by several agencies, including the British Hypertension Society (BHS) and US Association for the Advancement of Medical Instrumentation (AAMI). A joint BHS/AAMI set of guidelines is in preparation. These guidelines emphasize the suitability of ABPM devices for hypertensive patients and those under general anesthesia, and may not be applicable to ambulant individuals with heart failure and blood pressures at or below the lower end of the evaluated ranges. Prospective studies of the accuracy and reliability of ABPM devices, their clinical utility and research potential should be undertaken in patients with heart failure before their informal and uncontrolled use in this population becomes widespread.

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.

Increased risk of congestive heart failure among infarctions with nighttime onset

BACKGROUND

The onset of acute myocardial infarction varies by time of day, with a peak in the morning and a trough at night. Whether infarct-related complications differ by the timing of the infarction is unknown.

METHODS AND RESULTS

In the Determinants of Myocardial Infarction Onset Study, we performed chart reviews and face-to-face interviews with 3625 patients with acute myocardial infarction. We assessed the time of onset of symptoms, the presence of ventricular tachycardia or congestive heart failure, and peak creatine kinase levels (in 1043 patients). We found significant circadian variation in the risk of congestive heart failure (P =.001). The risk dropped from 17% for infarctions that began between 6 PM and midnight to 10% for infarctions that began between 6 AM and noon. Adjustment for differences in the time from symptom onset to presentation for care and use of thrombolytic agents did not change the results. We found no circadian variation in the risk of ventricular tachycardia or in peak creatine kinase levels.

CONCLUSIONS

The risk of congestive heart failure is highest among infarctions that begin at night. Further research may clarify whether this reflects differences in the pathophysiologic characteristics of infarction or the quality of medical care provided for daytime and nighttime infarctions.