Phrenic Nerve Block for Diaphragmatic Pain: Case Report.

Referred chronic shoulder pain may arise from diaphragmatic irritation. It can potentially be alleviated by blockade of the phrenic nerve. There is literature describing its use in acute pain conditions; yet for chronic pain, there are no reports. We present 2 cases of chronic diaphragmatic irritation causing ipsilateral referred shoulder pain. Patients experienced significant pain relief and a reduction in opioid consumption after receiving an ultrasound-guided phrenic nerve block. While the phrenic nerve block shows promise for pain relief, carefully evaluating its benefits and risks is recommended before considering its application in selected cases.

Value of high-output pace-mapping of the right phrenic nerve for enabling safe radiofrequency ablation of atrial fibrillation: insights from three-dimensional computed tomography segmentation.

AIMS: Right phrenic nerve (RPN) injury is a disabling but uncommon complication of atrial fibrillation (AF) radiofrequency ablation. Pace-mapping is widely used to infer RPN's course, for limiting the risk of palsy by avoiding ablation at capture sites. However, information is lacking regarding the distance between the endocardial sites of capture and the actual anatomic RPN location. We aimed at determining the distance between endocardial sites of capture and anatomic CT location of the RPN, depending on the capture threshold. METHODS AND RESULTS: In consecutive patients undergoing AF radiofrequency ablation, we defined the course of the RPN on the electroanatomical map with high-output pacing at up to 50 mA/2 ms, and assessed RPN capture threshold (RPN-t). The true anatomic course of the RPN was delineated and segmented using CT scan, then merged with the electroanatomical map. The distance between pacing sites and the RPN was assessed. In 45 patients, 1033 pacing sites were analysed. Distances from pacing sites to RPN ranged from 7.5 ± 3.0 mm (min 1) when RPN-t was ≤10 mA to 19.2 ± 6.5 mm (min 9.4) in cases of non-capture at 50 mA. A distance to the phrenic nerve > 10 mm was predicted by RPN-t with a ROC curve area of 0.846 [0.821-0.870] (P < 0.001), with Se = 80.8% and Sp = 77.5% if RPN-t > 20 mA, Se = 68.0% and Sp = 91.6% if RPN-t > 30 mA, and Se = 42.4% and Sp = 97.6% if non-capture at 50 mA. CONCLUSION: These data emphasize the utility of high-output pace-mapping of the RPN. Non-capture at 50 mA/2 ms demonstrated very high specificity for predicting a distance to the RPN > 10 mm, ensuring safe radiofrequency delivery.

Superior vena cava isolation using a pentaspline pulsed-field ablation catheter: feasibility and safety in patients undergoing atrial fibrillation catheter ablation.

AIMS: Superior vena cava (SVC) isolation during atrial fibrillation catheter ablation is limited by the risk of collateral damage to the sinus node and/or the phrenic nerve. Due to its tissue-specificity, we hypothesized the feasibility and safety of pulsed-field ablation (PFA)-based SVC isolation. METHODS AND RESULTS: One hundred and five consecutive patients undergoing PFA-based AF catheter ablation were prospectively included. After pulmonary vein isolation (±posterior wall isolation and electrical cardioversion), SVC isolation was performed using a standardized workflow. Acute SVC isolation was achieved in 105/105 (100%) patients after 6 ± 1 applications. Transient phrenic nerve stunning occurred in 67/105 (64%) patients but without phrenic nerve palsy at the end of the procedure and at hospital discharge. Transient high-degree sinus node dysfunction occurred in 5/105 (4.7%) patients, with no recurrence at the end of the procedure and until discharge. At the 3-month follow-up visit, no complication occurred. CONCLUSION: SVC isolation using a pentaspline PFA catheter is feasible and safe.

PolarX vs Arctic Front for Cryoballoon Ablation of Paroxysmal AF: The Randomized COMPARE CRYO Study.

BACKGROUND: Pulmonary vein isolation is an effective treatment for atrial fibrillation (AF). Cryoballoon ablation using the Arctic Front cryoballoon (Medtronic) was found to be superior to antiarrhythmic drug treatment. Recently, a novel cryoballoon system was introduced (PolarX, Boston Scientific). OBJECTIVES: The purpose of this study was to compare the efficacy and safety of the 2 cryoballoons in a randomized controlled trial. METHODS: Patients with symptomatic paroxysmal AF were enrolled in 2 centers and randomized 1:1 to pulmonary vein isolation using the PolarX or the Arctic Front cryoballoon. All patients received an implantable cardiac monitor. The primary endpoint was first recurrence of atrial tachyarrhythmia (AF, atrial flutter, or atrial tachycardia [AT]) between days 91 and 365. Procedural safety was assessed by a composite of tamponade, phrenic nerve palsy lasting >24 hours, vascular complications, stroke/transient ischemic attack, atrioesophageal fistula or death up to 30 days. RESULTS: A total of 201 patients were enrolled. At 1 year, recurrence of atrial tachyarrhythmia had occurred in 41 of 99 patients (41.6%) assigned to the PolarX group and in 48 of 102 patients (47.1%) assigned to the Arctic Front group (HR: 0.85 [95% CI: 0.56-1.30]; P = 0.03 for noninferiority; P = 0.46 for superiority). The safety endpoint occurred in 5 patients (5%) in the PolarX group (n = 5 phrenic nerve palsies lasting >24 hours), whereas no safety endpoints occurred in the Arctic Front group (P = 0.03). CONCLUSIONS: In this randomized controlled trial using implantable cardiac monitors for continuous rhythm monitoring, the novel PolarX cryoballoon was noninferior compared with the Arctic Front cryoballoon regarding efficacy. However, the PolarX balloon resulted in significantly more phrenic nerve palsies. (Comparison of PolarX and the Arctic Front Cryoballoons for PVI in Patients With Symptomatic Paroxysmal AF [COMPARE-CRYO]; NCT04704986).

Initial clinical experience with the balloon-in-basket pulsed field ablation system: acute results of the VOLT CE mark feasibility study.

AIMS: Pulsed field ablation (PFA) for the treatment of atrial fibrillation (AF) potentially offers improved safety and procedural efficiencies compared with thermal ablation. Opportunities remain to improve effective circumferential lesion delivery, safety, and workflow of first-generation PFA systems. In this study, we aim to evaluate the initial clinical experience with a balloon-in-basket, 3D integrated PFA system with a purpose-built form factor for pulmonary vein (PV) isolation. METHODS AND RESULTS: The VOLT CE Mark Study is a pre-market, prospective, multi-centre, single-arm study to evaluate the safety and effectiveness of the Volt™ PFA system for the treatment of paroxysmal (PAF) or persistent AF (PersAF). Feasibility sub-study subjects underwent phrenic nerve evaluation, endoscopy, chest computed tomography, and cerebral magnetic resonance imaging. Study endpoints were the rate of primary serious adverse event within 7 days and acute procedural effectiveness. A total of 32 subjects (age 61.6 ± 9.6 years, 65.6% male, 84.4% PAF) were enrolled and treated in the feasibility sub-study and completed a 30-day follow-up. Acute effectiveness was achieved in 99.2% (127/128) of treated PVs (96.9% of subjects, 31/32) with 23.8 ± 4.2 PFA applications/subject. Procedure, fluoroscopy, LA dwell, and transpired ablation times were 124.6 ± 28.1, 19.8 ± 8.9, 53.0 ± 21.0, and 48.0 ± 19.9 min, respectively. Systematic assessments of initial safety revealed no phrenic nerve injury, pulmonary vein stenosis, or oesophageal lesions causally related to the PFA system and three subjects with silent cerebral lesions (9.4%). There were no primary serious adverse events. CONCLUSION: The initial clinical use of the Volt PFA System demonstrates acute safety and effectiveness in the treatment of symptomatic, drug refractory AF.

Incidence of phrenic nerve injury during pulmonary vein isolation using different cryoballoons: data from a large prospective ablation registry.

AIMS: Phrenic nerve injury (PNI) is the most common complication during cryoballoon ablation. Currently, two cryoballoon systems are available, yet the difference is unclear. We sought to compare the acute procedural efficacy and safety of the two cryoballoons. METHODS: This prospective observational study consisted of 2,555 consecutive atrial fibrillation (AF) patients undergoing pulmonary vein isolation (PVI) using either conventional (Arctic Front Advance) (AFA-CB) or novel cryoballoons (POLARx) (POLARx-CB) at 19 centers between January 2022 and October 2023. RESULTS: Among 2,555 patients (68.8 ± 10.9 years, 1,740 men, paroxysmal AF[PAF] 1,670 patients), PVIs were performed by the AFA-CB and POLARx-CB in 1,358 and 1,197 patients, respectively. Touch-up ablation was required in 299(11.7%) patients. The touch-up rate was significantly lower for POLARx-CB than AFA-CB (9.5% vs. 13.6%, p = 0.002), especially for right inferior PVs (RIPVs). The touch-up rate was significantly lower for PAF than non-PAF (8.8% vs. 17.2%, P < 0.001) and was similar between the two cryoballoons in non-PAF patients. Right PNI occurred in 64(2.5%) patients and 22(0.9%) were symptomatic. It occurred during the right superior PV (RSPV) ablation in 39(1.5%) patients. The incidence was significantly higher for POLARx-CB than AFA-CB (3.8% vs. 1.3%, P < 0.001) as was the incidence of symptomatic PNI (1.7% vs. 0.1%, P < 0.001). The difference was significant during RSPV (2.5% vs. 0.7%, P < 0.001) but not RIPV ablation. The PNI recovered more quickly for the AFA-CB than POLARx-CB. CONCLUSIONS: Our study demonstrated a significantly higher incidence of right PNI and lower touch-up rate for the POLARx-CB than AFA-CB in the real-world clinical practice.

Can phrenic nerve injury be anticipated by larger cryoballoons?

Recently, a novel size-adjustable cryoballoon has been introduced in clinical practice, which can be inflated to two different diameters (28 and 31 mm). The 31 mm cryoballoon is specifically designed to achieve better contact with remodeled pulmonary veins (PVs) that have wider ostia while avoiding deep cannulation, thereby potentially reducing the risk of phrenic nerve injury (PNI) associated with deep balloon cannulation. However, we encountered two cases of PNI during cryoballoon ablation using the novel system among our initial 25 consecutive case series. Herein, we present two cases that exhibited PNI during freezing of the right superior PV with a size-adjustable balloon. While larger balloons are expected to create a larger area of isolation, the safety of this novel balloon system needs to be evaluated in a large-scale clinical study.

Contrast-enhanced computed tomography in the venous rather than the arterial phase is essential for the evaluation of the right phrenic nerve.

BACKGROUND: Preprocedural detection of the running course of the right pericardiophrenic bundles (PBs) is considered to be useful in preventing phrenic nerve (PN) injury during catheter ablation for atrial fibrillation (AF). However, previous studies using the arterial phase of contrast-enhanced computed tomography (CT) reported a relatively low right PBs detection rate. METHODS: This study included 63 patients with AF who underwent catheter ablation and preoperative contrast-enhanced CT imaging of the venous and arterial phases (66.7 ± 10.2 years; 44 male). The venous phase of contrast-enhanced CT significantly improved the detection rate of PBs compared to the arterial phase (96.8% vs. 60.3%, p < .001), and PBs were detected in the venous phase only in 23 (36.7%) patients. No significant differences were observed between the right PBs detection rate using non-contrast CT versus the arterial phase of contrast-enhanced CT (p = .37). Patients without visualization of the right PBs during the arterial phase had a higher frequency of chronic heart failure (p = .0083), lower left ventricular ejection fraction (p = .021), and a higher CHADS2 score (p = .048) than those with visualization. In five patients whose right PBs could only be detected during the venous phase of contrast-enhanced CT, the reconstructed running course of the right PBs corresponded with the PN generated by electrical high-output pacing. CONCLUSION: Contrast-enhanced CT images of the venous phase, rather than the arterial phase, are useful in detecting the right PBs, especially in patients with heart failure or reduced left ventricular ejection fraction.

Visualization and mapping of the right phrenic nerve by intracardiac echocardiography during atrial fibrillation ablation.

OBJECTIVE: This study aimed to evaluate the feasibility of real-time visualization and mapping of the right phrenic nerve (RPN) by using intracardiac echocardiography (ICE) during atrial fibrillation (AF) ablation. BACKGROUND: RPN injury is a complication associated with the ablation of AF. Multiple approaches are currently being used to prevent and detect RPN injuries. However, none of these approaches can directly visualize the RPN in real-time during the ablation procedure. METHODS AND RESULTS: The RPN was detected using ICE. The RPN and its adjacent structures were analysed. The relationship between the RPN's distance from the superior vena cava (SVC) and its pacing capture threshold was quantified. The safety of SVC isolation guided by the ICE-visualized RPN was evaluated. Thirty-eight people were enrolled in this study. The RPN was visualized by ICE in 92% of patients. It ran through the space between the SVC and the mediastinal pleura and had a 'straw'-like appearance upon ICE imaging. The course of the RPN was close to the SVC (minimum 1.0 ± 0.4 mm) and the right superior pulmonary vein (minimum 14.1 ± 7.3 mm). There was a positive linear correlation between the RPN's capture threshold and its distance from the SVC (Spearman's correlation coefficient = 0.728, < 0.001). SVC isolation was guided by the RPN; none of the patients developed an RPN injury. CONCLUSIONS: RPN can be visualized by ICE in most patients, thus providing a novel approach for the real-time detection of RPN during AF ablation.

Effect of respiratory training on respiratory failure secondary to unilateral phrenic nerve injury: A case report.

INTRODUCTION: Diaphragm is one of the most important respiratory muscles dominated by the phrenic nerve. Phrenic nerve injury would induce a series of clinical symptoms, including respiratory failure. Respiratory training could assist in regular treatment in improving the respiratory function and daily ability of respiratory failure patients. CASE PRESENTATION: A 71-years-old female was enrolled for the disorders of consciousness of 4.5 hours observed by her family and was diagnosed with respiratory failure secondary to unilateral phrenic nerve injury. The patient received basic therapy combined with rehabilitation training, including the training of aspirate muscle, limb resistance, thoracic loosening, aerobic training, electrical stimulation on respiratory nerves, and airway clearance. The combining therapeutic strategy significantly improved the daily ability and respiratory of the patient. The ultrasound showed that after therapy, the diaphragmatic muscles were thickened and the range of diaphragmatic movement was also enhanced. The pulmonary function was also improved after therapy. CONCLUSION: The combination of rehabilitation is suitable for the treatment of respiratory failure patients with clear causes of phrenic nerve injury. For patients with unexplained causes, rehabilitation could also be performed before the diagnosis. Patients with irreversible injury need long-term and family rehabilitation prescriptions.

The phrenic nerve; the forgotten nerve in head and neck surgery.

BACKGROUND: Neck dissection is a commonly performed procedure for oncologic control of head and neck malignancy. With contemporary modified radical and selective neck dissections, haematoma, wound infection, tissue necrosis, chyle leak and injury involving the marginal mandibular, hypoglossal, vagus or accessory nerves are commonly described complications. Although the phrenic nerve courses within the surgical planes explored during a neck dissection and has a vital function in innervating the diaphragm, few studies have been performed to investigate the exact incidence of post-operative phrenic nerve paresis. This study aims to review the literature as to the rate of phrenic nerve injury following neck dissection. METHODS: A systematic literature review was conducted from 2000 to 2022 including studies reporting on phrenic nerve paresis following neck dissection. RESULTS: In total, 11 studies were included. The reported rate of immediate post-operative phrenic nerve paresis ranged from 0% to 5.3%, with an average rate of 0.613% (12/1959). The reported rate of phrenic nerve paresis at follow-up (1 month-127 months) ranged from 0% to 4.7%, with an average rate of 1.035% (5/483). There were no cases of bilateral phrenic nerve paresis reported in this period. CONCLUSIONS: Phrenic nerve paresis is an uncommon complication following neck dissection, often asymptomatic and potentially underreported. Bilateral phrenic nerve paresis is exceedingly rare. Injury can be avoided by staying superficial to the prevertebral fascia when dissecting around the anterior scalene muscle. Routine phrenic nerve integrity monitoring is not commonly utilized but may aid intra-operative phrenic nerve identification or confirmation of function.

Comparison of phrenic nerve injury and its effect on the extrapulmonary vein structures with cryoballoon and hot-balloon ablation systems: considering the lesion created on the superior vena cava as a surrogate marker.

Preventing phrenic nerve injury (PNI) during balloon-based ablation is essential. The superior vena cava-right atrial (SVC-RA) junction is located just opposite the balloon position during right superior pulmonary vein (RSPV) ablation, and the phrenic nerve runs nearby on the lateral side. We compared the occurrence of PNI between the two balloon-based ablation systems and also the lesions created at the SVC-RA junction, which were expected to represent the effect on extra-PV structures. Cryoballoon ablation (CBA, n = 110) and hot-balloon ablation (HBA, n = 90) were performed in atrial fibrillation patients. High-density maps of the SVC-RA junction were created in 93 patients (CBA = 53, HBA = 40), and the damaged area (< 1.0 mV) was determined as an "SVC lesion". CBA had a higher occurrence of transient PNI (7.3% vs 1.1%, p = 0.035), but all recovered during the 6-month follow-up. An apparent SVC lesion was documented in 43% of the patients (40/93), and all patients with PNI had this lesion. CBA created a frequent (CBA vs HBA = 55% vs 28%, p = 0.008) and wider (0.8[0.4-1.7] cm2 vs 0.5[0.3-0.7] cm2, p = 0.005) SVC lesion than HBA. A multivariate analysis revealed that the use of a CBA system was a predictive factor of the occurrence of SVC lesions. CBA had a higher occurrence of transient PNI but not a permanent form. Every patient with PNI had lesions on the SVC-RA junction, and CBA revealed more substantial ablation effects at the SVC-RA junction than HBA. This may be caused by the different characteristics of the two balloon-based ablation systems and their balloon positions.

Optimal prevention method of phrenic nerve injury in superior vena cava isolation: efficacy of high-power, short-duration radiofrequency energy application on the risk points.

BACKGROUND OR PURPOSE: Superior vena cava isolation (SVCI) is widely performed adjunctively to atrial fibrillation (AF) ablation. Right phrenic nerve injury (PNI) is a complication of this procedure. The purpose of the study is to determine the optimal PNI prevention method in SVCI. METHODS: A total of 1656 patients who underwent SVCI between 2009 and 2022 were retrospectively examined. PNI was diagnosed based on the diaphragm position and movement in the upright position on chest radiographs before and after SVCI. RESULTS: With the introduction of various PN monitoring systems over the years, the incidence of SVCI-associated PNI has decreased. However, complete PNI avoidance has not been achieved. PNI incidence according to fluoroscopy-guided PN monitoring, high-output pace-guided, compound motor action potential-guided, and 3-dimensional electro-anatomical mapping (EAM) systems was 8.1% (38/467), 2.7% (13/476), 2.4% (4/130), and 2.8% (11/389), respectively. However, a high-power, short-duration (50 W/7 s) radiofrequency (RF) energy application only on PNI risk points tagged by a 3-dimensional EAM system completely avoids PNI (0%; 0 /160 since April 2021). PNI showed no symptoms and recovered within an average of 188 days post-SVCI, except for a few patients who required > 1 year. CONCLUSIONS: Although PNI incidence decreased annually with the introduction of various monitoring systems, these monitoring systems did not prevent PNI completely. Most notably, the delivery of a high-power, short-duration RF energy only on risk points tagged by EAM prevented PNI completely. PNI recovered in all patients. The application of higher-power, shorter-duration RF energy on risk points tagged by EAM appears to be an optimal PNI prevention maneuver.

Staged Phrenic Nerve Elongation and Free Functional Gracilis Muscle Transplantation-A Possible Option for Late Reconstruction in Chronic Brachial Plexus Injury.

PURPOSE: In patients with late brachial plexus birth injuries, sequelae after acute flaccid myelitis, or chronic adult brachial plexus injury, donor nerves for functioning muscle transplantation are often scarce. We present the results of a potential strategy using the phrenic nerve with staged free gracilis transplantation for upper extremity reanimation in these scenarios. METHODS: A retrospective review was performed on an institutional database of brachial plexus injury or patients with palsy. All patients underwent a staged reconstruction in which the ipsilateral phrenic nerve was extended by an autogenous nerve graft (PhNG), followed by free-functioning gracilis transplantation (PhNG-gracilis). RESULTS: Nine patients (6 cases of late brachial plexus birth injuries, 2 of acute flaccid myelitis, and 1 of adult chronic brachial plexus injury) were included in this study. The median follow-up period following the PhNG-gracilis procedure was 27 months (range, 12-72 months). The goals of the staged PhNG and PhNG-gracilis were primarily finger extension or finger flexion. In some patients, the technique was used to improve both elbow and finger function, tunneling the muscle through the flexor compartment of the upper arm and under the mobile wad at the elbow. All patients exhibited improvement of muscle strength, including in finger extension (4 patients) from M0 to M2; finger flexion (3 patients) from M0 to M3; elbow extension (1 patient) from M0 to M2; and elbow flexion (1 patient) from M2 to M4. CONCLUSIONS: A 2-stage PhNG-gracilis may restore or enhance the residual elbow and/or finger paralysis in chronic brachial plexus injuries. A minimum follow-up period of 3 years is recommended. This technique may remain useful as one of the last reconstructive options to increase power in patients with scarce donor nerves. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

3D mapping of phrenic nerve course for radiofrequency pulmonary vein isolation.

INTRODUCTION: Phrenic nerve (PN) injury is a rare but severe complication of radiofrequency (RF) pulmonary vein isolation (PVI). The objective of this study was to characterize the typical intracardiac course of the PN with a three-dimensional electroanatomic mapping system, to quantify the need for modification of the ablation trajectory to avoid delivering an ablation lesion on sites with PN capture, and to identify very circumscribed areas of common PNC on the routine ablation trajectory of a RF-PVI, allowing fast and effective PN screening for everyday usage. METHODS: We enrolled 137 consecutive patients (63 ± 9 years, 64% men) undergoing PVI. A detailed high output (20 mA) pace-mapping protocol was performed in the right (RA) and left atrium (LA) and adjacent vasculature. RESULTS: The right PN was most commonly captured in the superior vena cava at a lateral (50%) or posterolateral (23%) position before descending along the RA either straight (29%) or with a posterolateral bend (20%). In the LA, beginning deep within the right superior pulmonary vein (RSPV), the right PN is most frequently detectable anterolateral (31%), then descends to the lateral proximal RSPV (23%), and further towards the lateral antral region (15%) onto the medial LA wall (12%). To avoid delivering an ablation lesion on sites with PN capture, modification of ablation trajectory was necessary in 23% of cases, most commonly in the lateral RSPV antrum (81%). No PN injury occurred. CONCLUSION: PN mapping frequently reveals the close proximity of the PN to the ablation trajectory during PVI, particularly in the lateral RSPV antrum. Routine PN pacing should be considered during RF PVI procedures.

Characterization of Phrenic Nerve Response to Pulsed Field Ablation.

BACKGROUND: Phrenic nerve palsy is a well-known complication of cardiac ablation, resulting from the application of direct thermal energy. Emerging pulsed field ablation (PFA) may reduce the risk of phrenic nerve injury but has not been well characterized. METHODS: Accelerometers and continuous pacing were used during PFA deliveries in a porcine model. Acute dose response was established in a first experimental phase with ascending PFA intensity delivered to the phrenic nerve (n=12). In a second phase, nerves were targeted with a single ablation level to observe the effect of repetitive ablations on nerve function (n=4). A third chronic phase characterized assessed histopathology of nerves adjacent to ablated cardiac tissue (n=6). RESULTS: Acutely, we observed a dose-dependent response in phrenic nerve function including reversible stunning (R2=0.965, P<0.001). Furthermore, acute results demonstrated that phrenic nerve function responded to varying levels of PFA and catheter proximity placements, resulting in either: no effect, effect, or stunning. In the chronic study phase, successful isolation of superior vena cava at a dose not predicted to cause phrenic nerve dysfunction was associated with normal phrenic nerve function and normal phrenic nerve histopathology at 4 weeks. CONCLUSIONS: Proximity of the catheter to the phrenic nerve and the PFA dose level were critical for phrenic nerve response. Gross and histopathologic evaluation of phrenic nerves and diaphragms at a chronic time point yielded no injury. These results provide a basis for understanding the susceptibility and recovery of phrenic nerves in response to PFA and a need for appropriate caution in moving beyond animal models.

The many paths to diagnose diaphragmatic paralysis: Cardiopulmonary ultrasound on stage.

Abnormal diaphragmatic motion (ADM) due to phrenic nerve injury is a recognized complication of cardiac surgery and several diagnostic techniques can be used to determine the diagnosis. Due to its relationship with the diaphragm, cardiac kinetics is affected by the abnormal movement of the diaphragm in cases of left hemidiaphragm paralysis. The authors present a case of diaphragmatic paralysis in which the initial diagnosis is made through echocardiography.