Hemodynamic recognition of pure autonomic failure: A case report.

Neurogenic orthostatic hypotension (OH) causes severe orthostatic intolerance. We evaluated hemodynamic parameters in a patient with pure autonomic failure (PAF) using various unique approaches. A 60-year-old woman had worsening light-headedness, fatigue, and severe OH without compensatory tachycardia. PAF was diagnosed based on negative neurological findings, testing, and imaging results. The active standing test did not increase the heart rate (HR), and it decreased cardiac output, indicating impaired sympathetic control of cardiovascular activity. HR did not change during the supine bicycle exercise stress test, whereas blood pressure decreased. The patient had an accentuated reaction to isoproterenol but did not respond to atropine sulfate. Isoproterenol 0.01 µg/kg/min caused a 153 % increase in HR that required more than 30 min to return to its original value, suggesting hypersensitivity to catecholamines and decreased parasympathetic activity. As for why atropine sulfate (0.04 mg/kg) did not increase HR, we assumed that parasympathetic activity was already suppressed or the sympathetic effects were not predominant. Intravenous atropine sulfate may be useful in diagnosing PAF, which generally lacks specific neurological physical findings. A proper understanding of the hemodynamics involved in the management of PAF-associated OH is crucial. Learning objective: The autonomic control of cardiovascular function is impaired in pure autonomic failure, and neurogenic orthostatic hypotension can be diagnosed by evaluating changes in heart rate. Treatment should be based on the hemodynamic characteristics using non-invasive cardiac output monitoring, pharmacological approaches, and supine bicycle exercise stress tests.

Prognostic value of ECG monitor findings in COVID-19.

AIMS: COVID-19 can cause severe illness and multiorgan dysfunction. Acute myocardial damage has been detected in a significant portion of patients with COVID-19; therefore, several studies have reported that electrocardiographic findings could be used to evaluate the severalty of COVID-19. However, performing standard ECG for each patient hospitalised with COVID-19 can increase the level of exposure to COVID-19 among medical staff. Therefore, this study aimed to investigate the prognostic value of continuous electrocardiographic monitor findings in patients with COVID-19. METHODS: Among 1612 consecutive patients with COVID-19 who were admitted to our hospital between August 2021 and May 2022, we identified 96 (76±4 years) patients who underwent electrocardiographic monitor during hospitalisation. All electrocardiographic monitors were analysed by two independent cardiologists blinded to the clinical data of the patients. The endpoint was defined as the occurrence of all-cause mortality related to COVID-19. The event data were retrospectively gathered from the patients' medical records. A multivariate Cox model was used to assess whether these electrocardiographic monitor findings and clinical data were associated with in-hospital mortality. RESULTS: During a mean hospitalisation period of 22.8±3.2 days, in-hospital mortality occurred in 17 (18%) patients. Atrial fibrillation (HR: 3.95, 95% CI: 1.39 to 11.21) and lung disease complications (HR: 2.91, 95% CI: 1.06 to 7.98) were significant prognostic factors for death in multivariate analysis. Compared with the non-complicated lung disease and non-atrial fibrillation group, the risk of mortality was significantly higher in the lung disease complication and atrial fibrillation group in the multivariate Cox proportional model (HR: 8.37, 95% CI: 1.69 to 41.30, p=0.009). CONCLUSIONS: The simple method of ECG monitor could adequately detect atrial fibrillation. This study demonstrated that atrial fibrillation complicated with lung disease, could have potential prognostic value among patients with COVID-19.

Prediction of atrial fibrillation using a home blood pressure monitor with a high-resolution system.

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.

Moving dipole analysis of normal and abnormal ventricular activation by magnetocardiography.

The current source during ventricular excitation of the in situ heart has not been well characterized. We analyzed current dipoles of ventricular excitation by magnetocardiography (MCG) in 16 healthy subjects and 10 patients with the Wolff-Parkinson-White syndrome or premature ventricular contraction. Single current dipoles were estimated by MCG with the spatial position, direction, and strength in the initial 40 ms of QRS (moving dipole analysis). In 12 of the 16 healthy subjects, the origin of current dipoles moved consecutively from the initial position with the increase in the peak strength at 30 ms of QRS. In the other 4 healthy subjects, dipoles moved discontinuously jumping to the right-anterior thorax at 17.8 ms (mean). In abnormal ventricular excitation, the dipoles remained in the initial position with little movement, smaller strength of dipole than that of normal with a delayed peak time. The moving dipole analysis can be applied to determine spatial distribution of normal and abnormal excitation sources at the initial phase of ventricular depolarization in the in situ heart.