-
International Journal of Cardiology Jan 2019Many patients with atrial fibrillation (AF) present with stroke as their first clinical manifestation and since improved AF screening methods are thus required, we... (Observational Study)
Observational Study
BACKGROUND
Many patients with atrial fibrillation (AF) present with stroke as their first clinical manifestation and since improved AF screening methods are thus required, we investigated whether pulse rate variability parameters predict future AF and cerebrovascular events.
METHODS
In an observational cohort study of 5000 community-resident adults (58% male; 50-84 years), the beat-to-beat variability of suprasystolic brachial blood pressure waveforms was measured with root mean square of successive differences (RMSSD) and irregularity index (IrrIx). Based on outcome-oriented and previously validated thresholds for detecting AF, RMSSD and IrrIx were dichotomised at 100 ms and 7.7%, respectively. Participants were followed up for 4.6 years (median), accruing 249 AF and 120 cerebrovascular events in the total sample (n = 5000), and 133 AF and 90 cerebrovascular events among those without prior AF diagnosis (n = 4296).
RESULTS
In multivariable-adjusted analyses, an elevated RMSSD (>100 ms) or IrrIx (>7.7%) was strongly associated with a higher risk of AF (hazard ratios (HRs) = 2.00-2.95) and cerebrovascular events (HRs = 1.91-2.28), even among people without prior AF diagnosis: HRs for AF = 1.70-2.05 and cerebrovascular events = 2.00-2.28. These associations were strongest in the highest RMSSD tertile >100 ms or IrrIx tertile >7.7%: HRs for AF = 2.32-4.47 and cerebrovascular events = 2.43-3.69. Among those without prior AF diagnosis, the highest categorical net reclassification improvement for 5-year cerebrovascular risk was 14% (95% confidence interval: 7-21%).
CONCLUSIONS
Elevated RMSSD or IrrIx values indicative of the presence of AF predict future AF and cerebrovascular events; more so with increasing pulse irregularity and even among those without prior AF diagnosis.
Topics: Aged; Aged, 80 and over; Atrial Fibrillation; Blood Pressure; Electrocardiography; Female; Follow-Up Studies; Heart Rate; Humans; Incidence; Male; Middle Aged; New Zealand; Population Surveillance; Prognosis; Reproducibility of Results; Risk Assessment; Risk Factors; Stroke; Time Factors
PubMed: 30318296
DOI: 10.1016/j.ijcard.2018.10.026 -
Prediction of atrial fibrillation using a home blood pressure monitor with a high-resolution system.Open Heart Sep 2022The usefulness of screening for atrial fibrillation (AF) using several home blood pressure (BP) monitors has been reported. We evaluated the accuracy of a...
OBJECTIVE
The usefulness of screening for atrial fibrillation (AF) using several home blood pressure (BP) monitors has been reported. We evaluated the accuracy of a high-resolution system (HiRS) for AF prediction and its usefulness when installed in home BP monitors.
METHODS
In patients with paroxysmal, persistent or permanent AF, ECG recording and BP measurements were performed simultaneously. The relationship between ECG rhythm diagnosis and pulse irregularity recognition, using a home BP monitor with HiRS, was investigated. The severity of a pulse disturbance during BP measurement was displayed as an irregular pulse rhythm symbol (IPRS) in three instances. The IPRS was not displayed if the pulse was regular, turned on if there was a weak variation in the pulse, and blinked if there was a strong variation in the pulse.
RESULTS
One hundred and seven patients (44 paroxysmal AF, 63 persistent or permanent AF) were enrolled, and a total of 333 recordings were analysed. The rhythms recorded by each ECG were 73 sinus regular rhythms, 35 extrasystoles, 222 AFs and 3 atrial flutters. Sensitivity and specificity for the prediction of any arrhythmia by the IPRS display of the BP monitor were 95.8% (95% CI 92.6% to 97.6%) and 96.8% (95% CI 92.6% to 100%), respectively. In addition, sensitivity and specificity for the prediction of AF were 100% (95% CI 97.5% to 100%) and 74.8% (95% CI 65.6% to 82.5%), respectively. Sensitivity and specificity for the prediction of AF by the IPRS blinking display were 88.3% (95% CI 83.3% to 92.2%) and 94.6% (95% CI 88.6% to 98.0%%), respectively. IPRS exhibited lighting or blinking during AF occurrence; however, during sinus rhythm, IPRS was not displayed in 72 out of 73 recordings.
CONCLUSION
The IPRS device predicted AF with precision and may be particularly useful for predicting an arrhythmia attack in patients with paroxysmal AF.
Topics: Atrial Fibrillation; Blood Pressure Monitors; Electrocardiography; Heart Rate; Humans; Sensitivity and Specificity
PubMed: 36170999
DOI: 10.1136/openhrt-2022-002006 -
Comparative Biochemistry and... Dec 1999The dramatic fall in heart rate exhibited by mammals entering hibernation begins before there is any noticeable fall in body temperature. The initial, progressive... (Review)
Review
The dramatic fall in heart rate exhibited by mammals entering hibernation begins before there is any noticeable fall in body temperature. The initial, progressive decrease in heart rate is the result of a cyclic parasympathetic activation that induces skipped beats and regular asystoles as well as slows the even heart beat. As body temperature subsequently falls, the parasympathetic influence is progressively withdrawn and periods of parasympathetic and sympathetic dominance alternate and give rise to regular periods of arrhythmia (tachycardia followed by bradycardia), and occasional long asystoles or periods of highly irregular cardiac activity. Superimposed on this is a vagally-mediated, respiratory sinus arrhythmia that is accentuated in species that breathe episodically. These events give way to a uniform heart rate in deep hibernation at low temperatures where both parasympathetic and sympathetic tone appear absent. The complete absence of tone is not a function of reduced temperature but is reflective of the state of deep, steady state hibernation. The elevation in heart rate that accompanies the onset of arousal is the result of dramatic increases in sympathetic activation that precede any increases in body temperature. As body temperature then rises, sympathetic influence is slowly withdrawn. Arrhythmias are also common during natural arousals or shifts from lower to warmer hibernation temperatures as periods of parasympathetic and sympathetic dominance again alternate en route to re-establishing a steady state in euthermia. The mechanism behind, and the biological significance of, cardiac changes mediated through orchestrated arrhythmias remain unknown.
Topics: Animals; Autonomic Nervous System; Heart Rate; Hibernation; Mammals
PubMed: 10682236
DOI: 10.1016/s1095-6433(99)00130-0 -
Methods of Information in Medicine May 2016Heart rate variability (HRV) is a signal obtained from RR intervals of electrocardiography (ECG) signals to evaluate the balance between the sympathetic nervous system...
BACKGROUND
Heart rate variability (HRV) is a signal obtained from RR intervals of electrocardiography (ECG) signals to evaluate the balance between the sympathetic nervous system and the parasympathetic nervous system; not only HRV but also pulse rate variability (PRV) extracted from finger pulse plethysmography (PPG) can reflect irregularities that may occur in heart rate and control procedures.
OBJECTIVES
The purpose of this study is to compare the HRV and PRV during hypoglycemia in order to evaluate the features that computed from PRV that can be used in detection of hypoglycemia.
METHODS
To this end, PRV and HRV of 10 patients who required testing with insulin-induced hypoglycemia (IIHT) in Clinics of Endocrinology and Metabolism Diseases of Bezm-i Alem University (Istanbul, Turkey), were obtained. The recordings were done at three stages: prior to IIHT, during the IIHT, and after the IIHT. We used Bland-Altman analysis for comparing the parameters and to evaluate the correlation between HRV and PRV if exists.
RESULTS
Significant correlation (r > 0.90, p < 0.05) and close agreement were found between HRV and PRV for mean intervals, the root-mean square of the difference of successive intervals, standard deviation of successive intervals and the ratio of the low-to-high frequency power.
CONCLUSIONS
In conclusion, all the features computed from PRV and HRV have close agreement and correlation according to Bland-Altman analyses' results and features computed from PRV can be used in detection of hypoglycemia.
Topics: Algorithms; Female; Heart Rate; Humans; Hypoglycemia; Insulin; Male; Middle Aged; Pulse; Signal Processing, Computer-Assisted
PubMed: 27063926
DOI: 10.3414/ME15-01-0088 -
Journal of Clinical Hypertension... Nov 2017The authors evaluated a new algorithm for detecting atrial fibrillation (AF) using a home blood pressure monitor. Three serial blood pressure values were measured by the...
The authors evaluated a new algorithm for detecting atrial fibrillation (AF) using a home blood pressure monitor. Three serial blood pressure values were measured by the monitor in 16 patients with AF and 20 patients with sinus rhythm. The authors defined "monitor AF in irregular pulse peak (IPP) 25" as follows: (1) IPP: |interval of pulse peak - the average of the interval of the pulse peak| ≥ the average of the interval of the pulse peak ×25%; (2) irregular heart beat: beats of IPP ≥ total pulse ×20%; and (3) monitor AF: two or more irregular heart beats of the three blood pressure measurements. Cutoff IPP values were set at 20% (IPP20) and 15% (IPP15). The monitor's AF specificity was 1.0 in IPP25, IPP20, and IPP15, and its sensitivity was 0.88 in IPP25, 0.94 in IPP20, and 1.0 in IPP15. The new algorithm had high diagnostic accuracy for detecting AF and a low false-positive rate.
Topics: Aged; Algorithms; Atrial Fibrillation; Blood Pressure; Blood Pressure Monitoring, Ambulatory; Dimensional Measurement Accuracy; Female; Heart Rate; Humans; Hypertension; Male; Middle Aged; Reproducibility of Results; Sphygmomanometers
PubMed: 28861938
DOI: 10.1111/jch.13076 -
Europace : European Pacing,... Dec 2011
Topics: Algorithms; Atrial Fibrillation; Cardiac Resynchronization Therapy; Female; Heart Conduction System; Heart Rate; Heart Ventricles; Humans; Male
PubMed: 21873626
DOI: 10.1093/europace/eur276 -
Heart Rhythm Oct 2010
Topics: Arrhythmias, Cardiac; Electrocardiography; Electrophysiologic Techniques, Cardiac; Heart Conduction System; Heart Rate; Humans; Male; Middle Aged
PubMed: 20061186
DOI: 10.1016/j.hrthm.2009.11.018 -
Acta Physiologica Scandinavica Mar 2003Neurons in the rostral ventrolateral medulla (RVLM) that project directly to sympathetic preganglionic neurons in the spinal cord play a critical role in maintaining... (Review)
Review
AIM
Neurons in the rostral ventrolateral medulla (RVLM) that project directly to sympathetic preganglionic neurons in the spinal cord play a critical role in maintaining tonic activity in sympathetic vasomotor nerves. Intracellular recordings in vivo from putative RVLM presympathetic neurons have demonstrated that under resting conditions these neurons display an irregular tonic firing rate, and also receive both excitatory and inhibitory synaptic inputs. This paper will briefly review some recent findings on the role of glutamate, GABA and angiotensin II (Ang II) receptors in maintaining the tonic activity of RVLM presympathetic neurons.
RESULTS
Based on these findings, the following hypotheses will be discussed: (1) RVLM neurons receive tonic glutamatergic excitatory inputs, which originate from both medullary and supramedullary sources; (2) at least some neurons that project to and tonically inhibit RVLM presympathetic neurons are themselves tonically inhibited by GABAergic inputs originating from neurons in the caudalmost part of the ventrolateral medulla (caudal pressor area); (3) under normal conditions, Ang II receptors in the RVLM do not contribute significantly to the tonic activity of RVLM presympathetic neurons, but may do so in abnormal conditions such as heart failure or neurogenic hypertension; (4) RVLM presympathetic neurons maintain a significant level of tonic resting activity even when glutamate, GABA and Ang II receptors on the neurons are completely blocked. Under these conditions, the tonic activity is a consequence either of the intrinsic membrane properties of the neurons (autoactivity) or of synaptic inputs mediated by receptors other than glutamate, GABA or Ang II receptors.
CONCLUSION
The current evidence indicates that the resting activity of RVLM presympathetic neurons is determined by the balance of powerful tonic excitatory and inhibitory synaptic inputs. Ang II receptors also contribute to the raised resting activity of these neurons in some pathological conditions.
Topics: Angiotensin II; Animals; Bicuculline; Blood Pressure; Heart Rate; Kidney; Kynurenic Acid; Medulla Oblongata; Muscle Tonus; Muscle, Smooth, Vascular; Neurons; Pressoreceptors; Rats; Receptors, Angiotensin; Receptors, GABA; Receptors, Glutamate; Vasomotor System
PubMed: 12608991
DOI: 10.1046/j.1365-201X.2003.01070.x -
The Cochrane Database of Systematic... Apr 2013Atrial fibrillation (AF) is the most common arrhythmia in clinical practice and is a leading cause of morbidity and mortality. Screening for AF in asymptomatic patients... (Review)
Review
BACKGROUND
Atrial fibrillation (AF) is the most common arrhythmia in clinical practice and is a leading cause of morbidity and mortality. Screening for AF in asymptomatic patients has been proposed as a way of reducing the burden of the disease by detecting people who would benefit from prophylactic anticoagulation therapy prior to the onset of symptoms. However, for screening to be an effective intervention it must improve the detection of AF and provide benefit for those who are detected earlier as a result of screening.
OBJECTIVES
The primary objective of this review was to examine whether screening programmes increase the detection of new cases of AF compared to routine practice. The secondary objectives were to identify which combination of screening strategy and patient population is most effective, as well as assessing any safety issues associated with screening, its acceptability within the target population and the costs involved.
SEARCH METHODS
We searched the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library, MEDLINE (Ovid) and EMBASE (Ovid) up to March 2012. Other relevant research databases, trials registries and websites were searched up to June 2012. Reference lists of identified studies were also searched for potentially relevant studies and we contacted corresponding authors for information about additional published or unpublished studies that may be relevant. No language restrictions were applied.
SELECTION CRITERIA
Randomised controlled trials, controlled before and after studies and interrupted time series studies comparing screening for AF with routine practice in people aged 40 years and over were eligible. Two authors (PM, CT or MF) independently selected the trials for inclusion.
DATA COLLECTION AND ANALYSIS
Assessment of risk of bias and data extraction were performed independently by two authors (PM, CT). Odds ratios (OR) and 95% confidence intervals (CI) were used to present the results for the primary outcome, which is a dichotomous variable. Since only one included study was identified, no meta-analysis was performed.
MAIN RESULTS
One cluster randomised controlled trial met the inclusion criteria for this review. This study compared systematic screening (by invitation to have an electrocardiogram (ECG)) and opportunistic screening (pulse palpation during a general practitioner (GP) consultation for any reason followed by an ECG if pulse was irregular) to routine practice (normal case finding on the basis of clinical presentation) in people aged 65 years or older. The risk of bias in the included study was judged to be low.Both systematic and opportunistic screening of people over the age of 65 years are more effective than routine practice (OR 1.57, 95% CI 1.08 to 2.26 and OR 1.58, 95% CI 1.10 to 2.29, respectively). The number needed to screen in order to detect one additional case compared to routine practice was 172 (95% CI 94 to 927) for systematic screening and 167 (95% CI 92 to 806) for opportunistic screening. Both systematic and opportunistic screening were more effective in men (OR 2.68, 95% CI 1.51 to 4.76 and OR 2.33, 95% CI 1.29 to 4.19, respectively) than in women (OR 0.98, 95% CI 0.59 to 1.62 and OR 1.2, 95% CI 0.74 to 1.93, respectively). No data on the effectiveness of screening in different ethnic or socioeconomic groups were available. There were insufficient data to compare the effectiveness of screening programmes in different healthcare settings.Systematic screening was associated with a better overall uptake rate than opportunistic screening (53% versus 46%) except in the ≥ 75 years age group where uptake rates were similar (43% versus 42%). In both screening programmes men were more likely to participate than women (57% versus 50% in systematic screening, 49% versus 41% in opportunistic screening) and younger people (65 to 74 years) were more likely to participate than people aged 75 years and over (61% versus 43% systematic, 49% versus 42% opportunistic). No adverse events associated with screening were reported.The incremental cost per additional case detected by opportunistic screening was GBP 337, compared to GBP 1514 for systematic screening. All cost estimates were based on data from the single included trial, which was conducted in the UK between 2001 and 2003.
AUTHORS' CONCLUSIONS
Systematic and opportunistic screening for AF increase the rate of detection of new cases compared with routine practice. While both approaches have a comparable effect on the overall AF diagnosis rate, the cost of systematic screening is significantly more than that of opportunistic screening from the perspective of the health service provider. The lack of studies investigating the effect of screening in other health systems and younger age groups means that caution needs to be exercised in relation to the transferability of these results beyond the setting and population in which the included study was conducted.Additional research is needed to examine the effectiveness of alternative screening strategies and to investigate the effect of the intervention on the risk of stroke for screened versus non-screened populations.
Topics: Aged; Asymptomatic Diseases; Atrial Fibrillation; Electrocardiography; Female; Humans; Male; Mass Screening; Palpation; Pulse; Randomized Controlled Trials as Topic
PubMed: 23633374
DOI: 10.1002/14651858.CD009586.pub2 -
Medicinski Arhiv 2009In the last decades analysis of heart rate variability has emerged as a new useful tool for assessing the changes in autonomic tone that influences cardiovascular... (Review)
Review
In the last decades analysis of heart rate variability has emerged as a new useful tool for assessing the changes in autonomic tone that influences cardiovascular function. High variability of oscillations and the integrated physiologic activities of heart and cardiovascular system isassociated with physiologic functioning. Irregularity of the length of consecutive heart cycles, designated as heart rate variability, reflects the ability of cardiovascular system to adapt to different situations in everyday life. Reduction of these fluctuations of the heart periods has been shown to be associated with pathological conditions in many experimental and clinical trials. The extent and consistency of the reduction of heart rate variability in the patients after acute coronary events, were shown to be related to mortality and cardiovascular dysfunction. In patients with diabetes mellitus who develop autonomic neuropathy, reduced heart rate variability is quite common. Reduced heart rate variability was shown in endocrine disorders, neurological and psychiatric diseases, with use of different drugs and many other conditions. The most common ways of measuring heart rate variability are measuring in time domain analysis and frequency domain analysis. Parameters calculated from the measurements are related to the functions of sympathetic and parasympathetic nervous system. Measurements of changes in autonomic function is very important in the follow up in different diseases and for determination of the efficacy of the therapy. In the field of surgery and anaesthesia, besides preoperative risk stratification, there are many studies on the effects of different anaesthetics on heart rate variability. In this paper, some aspects of measurement of heart rate variability and changes of the values of parameters in different pathological conditions and clinical implications are reviewed.
Topics: Autonomic Nervous System; Electrocardiography, Ambulatory; Heart; Heart Rate; Humans
PubMed: 19537668
DOI: No ID Found