Airflow and Air Velocity Measurements While Playing Wind Instruments, with Respect to Risk Assessment of a SARS-CoV-2 Infection.

Due to airborne transmission of the coronavirus, the question arose as to how high the risk of spreading infectious particles can be while playing a wind instrument. To examine this question and to help clarify the possible risk, we analyzed 14 wind instruments, first qualitatively by making airflows visible while playing, and second quantitatively by measuring air velocity at three distances (1, 1.5, 2 m) in the direction of the instruments' bells. Measurements took place with wind instrumentalists of the Bamberg Symphony in their concert hall. Our findings highlight that while playing, no airflows escaping from any of the wind instruments-from the bell with brass instruments or from the mouthpiece, keyholes or bell with woodwinds-were measurable beyond a distance of 1.5 m, regardless of volume, pitch or what was played. With that, air velocity while playing corresponded to the usual value of 1 m/s in hall-like rooms. For air-jet woodwinds, alto flute and piccolo, significant air movements were seen close to the mouthpiece, which escaped directly into the room.

Long-term vagal stimulation for heart failure: Eighteen month results from the NEural Cardiac TherApy foR Heart Failure (NECTAR-HF) trial.

BACKGROUND: The NECTAR-HF study evaluated safety and feasibility of vagal nerve stimulation (VNS) for the treatment of heart failure patients. The first six-month randomized phase of the study did not show improvement in left ventricular remodelling in response to VNS. This study reports the 18-month results and provides novel findings aiming to understand the lack of efficacy of VNS, including a new technique assessing the effects of VNS. METHODS: Ninety-six patients were randomized 2:1 to active or inactive VNS for 6months, thereafter VNS was activated for all patients. The primary safety endpoint was 18-month all-cause mortality. RESULTS: Ninety-one patients continued in the long-term evaluation with active VNS. The on-therapy survival estimate at 18months was 95% with a 95% one-sided lower confidence limit of 91%, (better than the predefined criterion). Left ventricular systolic volume decreased in the crossover group (VNS OFF→ON; 144±37 to 139±40, p<0.05) after VNS activation; LVESD (5.02±0.77 to 4.96±0.82, p>0.05) and LVEF (33.2±4.9 to 33.3±6.5, p>0.05) did not change. A new technique to detect subtle heart rate changes during Holter recordings, i.e. "heat maps", revealed that VNS evoked heart rate response in only 13/106 studies (12%) at 6 and 12months with active VNS. CONCLUSIONS: Although a favourable long-term safety profile was found, improvements in the efficacy endpoints were not seen with VNS. A new technique for detecting acute heart rate responses to VNS suggests that the recruitment of nerve fibres responsible for heart rate changes were substantially lower in NECTAR-HF than in pre-clinical models.

Chronic vagal stimulation for the treatment of low ejection fraction heart failure: results of the NEural Cardiac TherApy foR Heart Failure (NECTAR-HF) randomized controlled trial.

AIM: The neural cardiac therapy for heart failure (NECTAR-HF) was a randomized sham-controlled trial designed to evaluate whether a single dose of vagal nerve stimulation (VNS) would attenuate cardiac remodelling, improve cardiac function and increase exercise capacity in symptomatic heart failure patients with severe left ventricular (LV) systolic dysfunction despite guideline recommended medical therapy. METHODS: Patients were randomized in a 2 : 1 ratio to receive therapy (VNS ON) or control (VNS OFF) for a 6-month period. The primary endpoint was the change in LV end systolic diameter (LVESD) at 6 months for control vs. therapy, with secondary endpoints of other echocardiography measurements, exercise capacity, quality-of-life assessments, 24-h Holter, and circulating biomarkers. RESULTS: Of the 96 implanted patients, 87 had paired datasets for the primary endpoint. Change in LVESD from baseline to 6 months was -0.04 ± 0.25 cm in the therapy group compared with -0.08 ± 0.32 cm in the control group (P = 0.60). Additional echocardiographic parameters of LV end diastolic dimension, LV end systolic volume, left ventricular end diastolic volume, LV ejection fraction, peak V02, and N-terminal pro-hormone brain natriuretic peptide failed to show superiority compared to the control group. However, there were statistically significant improvements in quality of life for the Minnesota Living with Heart Failure Questionnaire (P = 0.049), New York Heart Association class (P = 0.032), and the SF-36 Physical Component (P = 0.016) in the therapy group. CONCLUSION: Vagal nerve stimulation as delivered in the NECTAR-HF trial failed to demonstrate a significant effect on primary and secondary endpoint measures of cardiac remodelling and functional capacity in symptomatic heart failure patients, but quality-of-life measures showed significant improvement.

Rationale and study design of the NEuroCardiac TherApy foR Heart Failure Study: NECTAR-HF.

AIMS: Increased sympathetic activation and reduced parasympathetic tone are important pathophysiological contributors to the progression of heart failure, and are associated with poor outcome in patients. The aim of this study is to determine if vagal nerve stimulation (VNS) is a promising approach to modulate autonomic function and slow cardiac remodelling and the progression of heart failure. METHODS: The NECTAR-HF (NEural Cardiac TherApy foR Heart Failure) trial is designed to evaluate whether the Boston Scientific VNS device is safe and may attenuate cardiac remodelling, improve cardiac function and increase exercise capacity, in symptomatic heart failure patients (New York Heart Association Class II-III) with left ventricular systolic dysfunction (ejection fraction ≤35%) and receiving optimal medical therapy. Patients will be randomized in a 2:1 ratio to receive standard optimal medical treatment plus VNS system in an active mode vs. optimal medical treatment plus VNS system in an inactive mode, for a 6 month period. After the 6 month control period, inactive VNS systems will be activated and all patients will receive VNS. The study is powered to detect differences in the primary efficacy endpoint of change in left ventricular end systolic diameter. Secondary endpoints include ejection fraction, left ventricular volumes, quality of life scores, functional capacity, and changes in biomarkers. CONCLUSION: This Phase II, randomized clinical trial conducted with vagal stimulation for heart failure will provide important new information on the potential of this novel and promising technique.

Performance evaluation of a right atrial automatic capture verification algorithm using two different sensing configurations.

BACKGROUND: This acute data collection study evaluated the performance of a right atrial (RA) automatic capture verification (ACV) algorithm based on evoked response sensing from two electrode configurations during independent unipolar pacing. METHODS: RA automatic threshold tests were conducted. Evoked response signals were simultaneously recorded between the RA(Ring) electrode and an empty pacemaker housing electrode (RA(Ring)-->Can) and the electrically isolated Indifferent header electrode (RA(Ring)-->Ind). The atrial evoked response (AER) and the performance of the ACV algorithm were evaluated off-line using each sensing configuration. An accurate threshold measurement was defined as within 0.2 V of the unipolar threshold measured manually. Threshold tests were designed to fail for small AER (< 0.35 mV) or insufficient signal-to-artifact ratio (SAR < 2). Manual threshold measurements were obtained during RA unipolar and bipolar pacing and compared across device indications. RESULTS: Data were collected from 38 patients with RA bipolar leads from four manufacturers. AER signals were analyzed from 34 patients who were indicated for a pacemaker (five), implantable cardioverter-defibrillator (11), or cardiac resynchronization therapy pacemaker (six) or defibrillator (12). The minimum AER amplitude was larger (P < 0.0001) when recorded from RA(Ring)-->Can (1.6+/-0.9 mV) than from RA(Ring)-->Ind (1.3+/-0.8 mV). The algorithm successfully measured the pacing threshold in 96.8% and 91.0% of tests for RA(Ring)-->Can and RA(Ring)-->Ind, respectively. No statistical difference between the unipolar and bipolar pacing threshold was observed. CONCLUSIONS: The RA(Ring)-->Can AER sensing configuration may provide a means of implementing an independent pacing/sensing method for ACV in the RA. RA bipolar pacing therapy based on measured RA unipolar pacing thresholds may be feasible.

Acquired left ventricular noncompaction as a cardiac manifestation of neuromuscular disorders.

OBJECTIVES: In single cases left-ventricular-hypertrabeculation/noncompaction (LVHT) develops after birth (acquired-LVHT). This study aimed to determine the prevalence of acquired-LVHT, to look for echocardiographic similarities between acquired-LVHT cases, to determine the interval between the last normal echocardiography and detection of acquired-LVHT, and which neuromuscular-disorders are associated with acquired-LVHT. DESIGN: We retrospectively looked for acquired-LVHT among a cohort of 22 LVHT-patients, diagnosed during 3 years. We compared cardiac and extra-cardiac findings between patients with acquired-LVHT. RESULTS: Among the 22 patients with LVHT, acquired-LVHT was found in four of them. One of the four was echocardiographically normal when investigated before the detection of LVHT. At diagnosis of LVHT echocardiography showed cardiac abnormalities in addition to LVHT in three of the four patients. The last echocardiography without LVHT was carried out on the average 3.8 y before LVHT was detected. Two patients had a dystrophinopathy and two patients a metabolic myopathy. CONCLUSION: Acquired-LVHT is more frequent than previously thought, requires review of previous echocardiographies, is largely associated with other cardiac abnormalities, and occurs most frequently together with neuromuscular-disorders.

The use of telescoping guide catheters for coronary sinus cannulation and sub-selecting tributaries in left ventricular lead placement.

INTRODUCTION: Failure to enter the coronary sinus (CS) with a guiding catheter and entering its tributaries remains challenging in left ventricle (LV) pacing lead implants for cardiac resynchronization therapy (CRT). A dual telescoping catheter system (8F outer/6F inner) is designed to provide the ability to adjust the catheter curve size, shape and/or reach to the patients' anatomy avoiding the need for catheter change. METHODS: Five different designs for CS cannulation were randomly tested in 64 patients scheduled for CRT device implant. RESULTS: In 33 consecutive patients three adaptable telescoping guiding catheter systems were tested per patient, the adaptable catheters had higher overall cannulation success rates (68, 63 and 62%) compared to the fixed shape catheter (46%) and an greater cannulation success rate when the CS location was not known (70, 53 and 72% vs 33% for the fixed shape). In a second group of 31 CRT patients the two telescoping catheters had similar high levels of success (71-80%), with or without using the inner catheter. CONCLUSIONS: The telescopic system is adaptable to a wide range of anatomical variations in patients and can result in a higher CS cannulation success rate due to its adjustability in the RA in search for the CS ostium. On top of this the inner catheter allows for sub-selecting the CS tributaries.

Clinical evaluation of two different evoked response sensing methods for automatic capture detection in the left ventricle.

BACKGROUND: This acute feasibility study compared two different automatic capture detection methodologies, the reduced coupling capacitor (RCC) and the independent pace/sense (IPS) methods, for the left ventricle (LV). METHODS: LV threshold tests were performed in DDD mode, with LV-only and bi-ventricular (BiV) pacing using an external cardiac resynchronization therapy (CRT) defibrillator. Evoked response (ER) signals from LV leads were recorded using the LV(Tip) (LV(Tip)-->Can) and LV(Ring) (LV(Ring)-->Can) to empty pulse generator (Can) housing sensing vectors to evaluate the two methodologies. Pacing vector, pulse duration, atrioventricular delay, and interventricular delay were varied to assess their effects on ER. The minimum ER amplitude (ER(min)), signal-to-artifact ratio (SAR), and ER amplitude voltage dependence were evaluated. ER(min)>2 mV and SAR(min)>2 define potential automatic LV capture detection for the two methodologies. RESULTS: Data collected from 43 patients (63.7 +/- 11.0 years) were analyzed, including unipolar and bipolar (14/29) LV leads. Neither ER sensing method was affected by changing the pacing vector. The LV(Tip)-->Can ER(min) was significantly decreased at the 1.0-ms pulse duration when compared to 0.4-ms (p < 0.05). During BiV pacing, LV(Tip)-->Can ER(min) increased at negative interventricular delays and decreased at positive interventricular delays relative to simultaneous pacing. LV(Tip)-->Can resulted in fewer patients with sufficient ER characteristics for capture detection, albeit only significantly at the extended pulse duration (79% vs 97%, p < 0.05) and at simultaneous and positive interventricular delays (81% vs 97%, p < 0.05). CONCLUSIONS: Though LV capture detection was feasible using both investigated methods, the RCC method (LV(Tip)-->Can) sensitivity to the evaluated pacing parameters suggests the IPS method (LV(Ring)-->Can) provides a more robust performance.

A wave-packet simulation of the low-lying singlet electronic transitions of acetylene.

The vibronic structure of the S0 --> S1 and the S0 --> S2 electronic transitions of acetylene is studied theoretically based on an ab initio quantum-dynamical approach. The underlying potential-energy surfaces and transition dipole moment functions are obtained from high-level multireference calculations, including the Davidson correction. Ensuing quantum-dynamical simulations rely on the wave-packet propagation method, using grid techniques, and including three nuclear degrees of freedom (C-C stretching and both HCC bending modes for J = 0). The importance of strong anharmonicity is assessed, especially for the S2 excited state with its unusual potential-energy surface. Good overall agreement with the experimental UV absorption spectrum of acetylene is achieved in the range of 6-8 eV.

Comparative prospective randomized efficacy testing of different guiding catheters for coronary sinus cannulation in heart failure patients.

INTRODUCTION: The efficacy of different shapes of guiding catheters for coronary sinus (CS) cannulation was evaluated at implant of a cardiac resynchronization therapy device that required transvenous placement of a pacing lead in a coronary vein on the left ventricle. METHODS AND RESULTS: Comparative testing of 5 different guiding catheter shapes was attempted in 29 consecutive patients. Four newer guiding catheters were tested in a prospective randomized manner with a reference standard catheter always tested in the last place. All of the new catheters included a distal shape that consisted of a single curve or a compound set of curves at the catheter tip, followed by a catheter shaft design which fell into one of two classes: (1). straight shaft catheters and (2). curved shaft catheters. The curved shaft class of catheters, two new and one standard, achieved higher (16/23 (70%), 17/23 (74%) and 17/22 (77%)) CS cannulation success rates than the straight shaft class catheters ((13/23 (56%) and 12/23 (52%)). The pairing of two catheters, one from each class in a single patient, or both from the curved shaft class resulted in a combined CS cannulation success rate of up to 96%. Two of the catheters were more effective from a left hand insertion than from a right hand insertion site. CONCLUSIONS: The ability to switch between guiding catheters with different shapes and compound curves can improve the CS cannulation success rate. The selection of guiding catheters should be influenced by the intended use of the catheter either from the left or from the right hand side.

Defibrillation efficacy and pain perception of two biphasic waveforms for internal cardioversion of atrial fibrillation.

UNLABELLED: Efficacy and Pain Perception of Two Biphasic Waveforms. INTRODUCTION: We evaluated the influence of the peak voltage of waveforms used for internal cardioversion of atrial fibrillation on defibrillation efficacy and pain perception. A low peak voltage biphasic waveform generated by a 500-microF capacitor with 40% tilt was compared to a standard biphasic waveform generated by a 60-microF capacitor with 80% tilt. METHODS AND RESULTS: In 19 patients with paroxysmal atrial fibrillation (79% male, age 55 +/- 11 years, 21% with heart disease), the atrial defibrillation threshold (ADFT) was determined during deep sedation with midazolam for both waveforms in a randomized fashion using a step-up protocol. Internal cardioversion with a single lead (shock vector: coronary sinus to right atrium) was successful in 18 (95%) of 19 patients. ADFT energy and peak voltage were significantly lower for the low-voltage waveform (2.1 +/- 2.4 J vs 3.5 +/- 3.9 J, P < 0.01; 100 +/- 53 V vs 290 +/- 149 V, P < 0.01). Sedation then was reversed with flumazenil after ADFT testing. Two shocks at the ADFT (or a 3-J shock if ADFT >3 J) were administered to the patient using each waveform in random order. Pain perception was assessed using both a visual scale and a numerical score. ADFTs were above the pain threshold in 17 (94%) of 18 patients, even though the ADFT with the 500-microF waveform was <100 V in 63% of the patients. Pain perception was comparable for both waveforms (numerical score: 6.5 +/- 2.4 vs 6.3 +/- 2.6; visual scale: 5.4 +/- 2.6 vs 5.2 +/- 3.1; P = NS, 500-microF vs 60-microF). The second shock was perceived as more painful in 88% of the patients, independent of the waveform used. CONCLUSION: Despite a 66% lower peak voltage and a 40% lower energy, the 40% tilt, 500-microF capacitor biphasic waveform did not change the pain perceived by the patient during delivery of internal cardioversion shocks. Pain perception for internal cardioversion probably is not influenced by peak voltage alone and increases with the number of applied shocks.

Human experience with transvenous biventricular defibrillation using an electrode in a left ventricular vein.

This study investigated the safety and feasibility of transvenous biventricular defibrillation in ICD patients. Some patients may have high DFTs due to weak shock field intensity on the LV. Animal studies showed a LV shocking electrode dramatically lowered DFTs. This approach might benefit heart failure patients already receiving a LV lead or conventional ICD patients with high DFTs. A modified guidewire was used as a temporary left venous access defibrillation electrode (LVA lead). In 24 patients receiving an ICD, the LVA lead was advanced through a guide catheter in the coronary sinus (CS) and into a randomized LV vein (anterior or posterior) using a venogram for guidance. Paired DFT testing compared a standard right ventricular defibrillation system to a biventricular defibrillation system. There were no complications or adverse events. As randomized, LVA lead insertion success was 87% and 71% for anterior and posterior veins, respectively, and 100% after crossover. Total insertion process time included venogram time (32.5 +/- 26.9 minutes, range 5-115, mode 15 minutes) and LVA lead insertion time (15 +/- 14 minutes, range 1-51, mode 7 minutes). An apical LVA lead position was achieved in 11 (45%) of 24 patients and 7 (64 %) of these 11 displayed a DFT reduction; however, mean DFTs were not statistically different. Transvenous biventricular defibrillation is feasible and was safe under the conditions tested. Additional clinical studies are justified to determine if optimized LV lead designs, lead placement, and shock configurations can yield the same large DFT reductions as observed in animals.