Bioimpedance Spectroscopy Reveals Important Association of Fluid Status and T1 -Mapping by Cardiovascular Magnetic Resonance.

BACKGROUND: Extracellular matrix expansion is a key pathophysiologic feature in heart failure and can be quantified noninvasively by cardiac magnetic resonance T1 -mapping. Free water within the interstitial space of the myocardium, however, may also alter T1 -mapping results. PURPOSE: To investigate the association between systemic fluid status and T1 -mapping by cardiac magnetic resonance. STUDY TYPE: Prospective, observational single-center study. POPULATION: Two-hundred eighty-five consecutive patients (44.4% female, 70.0 ± 14.9 years old) scheduled for cardiac MR due to various cardiac diseases. SEQUENCE AND FIELD STRENGTH: 1.5-T scanner (Avanto Fit, Siemens Healthineers, Erlangen, Germany). For T1 -mapping, electrocardiographically triggered modified-Look-Locker inversion (MOLLI) recovery sequence using a 5(3)3 prototype on a short-axis mid-cavity slice and with a four-chamber view was performed. ASSESSMENTS: MR parameters including native myocardial T1 -times using MOLLI and extracellular volume (MR-ECV) were assessed, and additionally, we performed bioimpedance analysis (BIA). Furthermore, demographic data and comorbidities were assessed. STATISTICS: Wilcoxon's rank-sum test, chi-square tests, and for correlation analysis, Pearson's correlation coefficients were used. Regression analyses were performed to investigate the association between patients' fluid status and T1 -mapping results. A P-value <0.05 was considered statistically significant. RESULTS: The mixed cohort presented with a mean overhydration (OH) of +0.2 ± 2.4 liters, as determined by BIA. By MR, native T1 -times were 1038 ± 51 msec and MR-ECV was 31 ± 9%. In the multivariable regression analysis, only OH was significantly associated with MR-ECV (adj. beta: 0.711; 95% CI: 0.28 to 1.14) along with male sex (adj. beta: 2.529; 95% CI: 0.51 to 4.55). In linear as well as multivariable analysis, only OH was significantly associated with native T1 times (adj. beta: 3.750; 95% CI: 1.27 to 6.23). CONCLUSION: T1 -times and MR-ECV were significantly associated with the degree of OH on BIA measurement. These effects were independent from age, sex, body mass index, and hematocrit. Patients' volume status may thus be an important factor when T1 -time and MR-ECV values are interpreted. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 3.

Landiolol for refractory tachyarrhythmias in the intensive care unit: case reports.

Tachyarrhythmias are common complications of critically ill patients treated on intensive care units. Landiolol is an ultra-short acting beta-blocker with a very high beta1-selectivity. Therefore, landiolol effectively reduces heart rate with only minimal negative effects on blood pressure and inotropy. This article describes two cases of successful treatment of supraventricular and ventricular tachycardias with landiolol in critically ill patients.

Atrial arrhythmias following surgical AF ablation: electrophysiological findings, ablation strategies, and clinical outcome.

BACKGROUND: Intraoperative atrial fibrillation (AF) ablation during cardiac surgery is a well-established treatment. However, tachycardia mechanisms, ablation strategies, and long-term follow-up of atrial arrhythmias (AA) following intraoperative AF ablation (AFA) have not been previously studied in a large cohort of patients. OBJECTIVE: Eighty-two patients (48 male, median age of 65 years) with symptomatic recurrence of AA following intraoperative AFA underwent radiofrequency catheter ablation. METHODS: Regular atrial tachycardias (AT) were mapped using 3-dimensional (3D) color-coded entrainment/activation mapping and eliminated by linear ablation. Pulmonary vein (PV)-isolation (PVI) was achieved in patients with left atrium-PV (LAPV) conduction after AT elimination. RESULTS: In 85 (83%) out of a total of 103 regular ATs, the entire reentrant circuits were localized perimitrally (n = 27), around PVs (left PV [LPV] or right PV [RPV]; n = 9), around left atrial appendage (LAA; n = 1), on left-sided atrial septum (n = 8), on atrioventricular nodal area (n = 1), on the posterior wall of LA (n = 1), along roof-septum-inferoposterior wall (n = 8), at coronary sinus ostium (n = 2), upper loop in RA (n = 1), and as cavotricuspid isthmus-dependent reentrant ATs (n = 27). Sixty-five (79%) patients received PVI. Noninducibility of any AT was reached at the end of all procedures. During a median follow-up time of 18 months, 69 patients (87%) were free of AA. CONCLUSION: Reentrant AT appears in the majority of patients with recurrence of AA following intraoperative AFA. Detailed 3D color-coded entrainment mapping was successfully obtained in the majority of patients suffering from reentrant AT after intraoperative AFA, facilitated the accurate identification of the entire reentrant circuit and selection of optimal ablation lines.

Two completely separated arrhythmias in one single heart chamber.

A 61-year-old male patient underwent an electrophysiological study and ablation for symptomatic atypical atrial flutter which was most likely related to previous intraoperative cryoablation for treatment of paroxysmal atrial fibrillation during open heart surgery. During the procedure, a tachycardia was induced in the electrically isolated left inferior pulmonary vein (PV). With the routine induction protocol, perimitral flutter was induced, whereas, independently, the PV tachycardia was still maintained. After ablation of the mitral isthmus, no tachycardias were inducible anymore.