Unilateral Atrial Ectopic Rhythm in a Golden Retriever

Background: Atrial ectopic rhythm is a type of supraventricular arrhythmia, originating in two distinct points in the atrial region. In the electrocardiographic (ECG) tracing, it is represented by independent depolarizations of sinus P waves and ectopic P waves. The occurrence of this disorder is rare, and the diagnosis criteria are the presence of the described waves within the basal rhythm. In humans, there have been reports related to severe heart failure with an unfavorable prognosis. The present report aimed to describe the clinical case of a dog with unilateral atrial ectopic rhythm without any underlying cardiac disorder.Case: A 8-year-old male golden retriever was brought to a veterinary clinic for a preoperative evaluation for lipoma removal in the right forelimb. On clinical examination, the owner stated that the patient was active, with no signs of easy fatigue or cough. The canine displayed normophagy, normodipsia, normoquezia, and normouria. On physical examination, he demonstrated a lymphatic temperament with tachypnea. The temperature and capillary filling time were within the normal range, with a normokinetic pulse. Cardiac auscultation revealed a mild grade I/VI murmur in mitral focus and an 80-bpm heart rate. Respiratory auscultation revealed the presence of harshy lung sounds. The cough reflex was positive; the Piparote test, negative. The blood test showed no noticeable changes in blood count and serum biochemistry. Systemic systolic blood pressure was 120 mmHg. On radiographic examination, no evidence of heart or lung abnormalities were identified. After the clinical evaluation, an ECG examination was performed; a unilateral atrial ectopic rhythm was observed with different frequencies between atrial and ventricular rhythm and with P (164°) and P waves (80°). On echocardiographic examination, no morphological abnormalities were seen, though trivial mitral insufficiency was identified in a color Doppler study. Blood was collected to measure electrolytes to check for possible electrolytic abnormalities; the results were within the normal range. The patient was released for and remained stable throughout the procedure, maintaining the rhythm detected during the transoperatory time. Upon reassessment in a new ECG examination, the arrhythmia persisted, suggesting that a primary lesion in the atrial tissue was present.Discussion: An atrial ectopic rhythm diagnosis requires a detailed study with the aim of ruling out heart diseases that may affect the propagation of the cardiac stimulus. However, no morphological or functional abnormalities of note that justified triggering stimuli for the ectopic rhythm were observed. In addition, based on the echocardiographic evaluation, myocardial function was preserved, supporting the canine’s release for the procedure. The suspicion of hydroelectrolytic alteration and hypoxia was present after discarding structural causes, though it was discarded due to normal laboratory results. The presence of ectopic P waves was due to the non-interference in the sinus P’ waves; consequently, they were found in the sinus heart rhythm. Upon assessing the ectopic P wave frequency, the atrial rhythm frequency was higher than the heart rate, juxtaposing the different irregular intervals within the atrial cycle. The rhythm alone may explain that its severity can be linked to the physical findings. This indicated that they did not influence the presentation of ectopia since the cardiac output, controlled by the sinus rhythm part, was responsible for maintaining the rhythm and the demand of the organism; the electrical conduction system, responsible for atrial systole, represents 15-25% of the blood ejection for the ventricular filling. Patients with rhythm disorders as described need guidance and follow-up for the early detection of clinical signs resulting from the destabilization of the condition.Keywords: atrial dissociation, supraventricular arrhythmia, electrocardiogram, dogs

Pulmonary stenosis in a dog submitted to valvuloplasty

The Congenital heart diseases are characterized by morphological defects in the embryonic development and the most frequent in dogs are: pulmonary and aortic valve stenosis, ventricular septal defect and persistente ductus arteriosus.  They may occur asymptomatically or even evolve to congestive heart failure. The definitive diagnosis is made through the visualization of the alterations in the echocardiogram. In the present report, a French Bulldog, three month old, asymptomatic was presented to a private Veterinary practice in Rio de Janeiro, Brazil. Cardiac auscultation evidenced a systolic heart murmur in tricuspid focus and diastolic murmur in pulmonary focus. To better evaluate the dog  chest radiography, electrocardiogram and echocardiogram were perfomed and  allowed the diagnosis of pulmonary stenosis. The clinical treatment with beta-blocker was installed and the surgical procedure was performed with the ballon valvuloplasty. The aim of this study was to report a case of pulmonary artery stenosis in a puppy, treated clinically and surgically, emphasizing the importance of the physical and complementary cardiological exams

Estudo da variabilidade da frequência cardíaca, por meio de eletrocardiografia contínua, em cães obesos, antes e após dieta terapêutica para emagrecimento.

O sistema nervoso autônomo (SNA) exerce papel de regulação do sistema cardiovascular por meio da modulação simpática e parassimpática, que atuam de maneira associadas na regulação da homeostase (Pumprla et al. 2002). Este balanço exercido pelo SNA é determinado por inúmeros fatores incluindo a respiração, estresse, temperatura, pressão sanguínea e atividade física (Vanderlei et al. 2009). A regulação nervosa cardíaca sofre influência da obesidade, mas ainda não foi esclarecida qual a resposta autonômica presente neste distúrbio (Pascon 2009). Sabe-se que o aumento de 10% da gordura corpórea é capaz de levar à diminuição da ação parassimpática e aumento da frequência cardíaca (Van Vliet et al. 1995). A Variabilidade da Frequência Cardíaca (VFC) permite avaliar a modulação autonômica sobre o coração, por meio dos intervalos de despolarizações ventriculares, ao eletrocardiograma (ECG), e fornece informações sobre a relação e contribuição do SNA na influência neural do controle da frequência cardíaca (Kleiger et al. 2005). O presente estudo tem por objetivo avaliar a VFC, por meio de exame eletrocardiográfico, em cães obesos, com Escore de Condição Corporal (ECC) 8/9 e 9/9, comparando com a VFC dos mesmos animais, após terapia com ração terapêutica no período de 6 meses

Unusual pulmonary thromboembolism in a Dirofilaria immitis infected dog

The nematode Dirofilaria immitis and its endosymbiont Wolbachia are the agents of canine heartworm (HW) disease. The worm´s main habitats are the pulmonary arteries, which elicit inflammation and disorders of the coagulation process. Clinical signs vary according to multiple factors, including worm burden, individual reaction, and duration of infection. This report describes an unusual case of pulmonary thromboembolism secondary to HW infection. A 7-year-old female dachshund presented with a history of cough, dyspnea, and two syncope episodes. On physical examination, the oral mucosa was slightly discolored, the femoral pulse was weak, respiratory distress was present, and the abdomen distended. Echocardiography showed severe right atrioventricular and pulmonary artery enlargement and a large structure with high echogenicity in the artery. After the dog died naturally, the lungs and heart were examined. Only one worm was found in the right ventricle, and a large thrombus was found in the main pulmonary artery. Histologically, fibrin thrombi and fragments of parasites were present inside the pulmonary artery branches. These findings highlight the importance of a thorough clinical evaluation of HW patients and confirm that only a few worms can threaten an animal’s life. Therefore, veterinarians must enforce chemoprophylaxis once treatment is life threatening

How does Dirofilaria immitis infection impact the health of dogs referred to cardiology care

Dirofilaria immitis is a nematode that can cause a disease that may present clinical signs from severe to absent. When dogs are symptomatic, the clinical signs are cardiorespiratory and nonspecific, which may be misleading. This study aimed to demonstrate the clinical presentations to cardiac care by evaluating 26 dogs subjected to clinical examination, complete blood count (CBC), specific tests for D. immitis infection, chest radiography, and echocardiography. Among them, 11 (42.3%) dogs were infected and 15 (57.7%) were non-infected. Most dogs presented with coughing (65.4%) and abnormal lung sounds (81%) independent of infection. Murmur at the tricuspid focus was present in 26.9% of the dogs, of which 57.1% were infected. Echocardiography revealed tricuspid regurgitation in 30.8% of the dogs and pulmonary regurgitation in 46.1%, of which 37.5% and 50% were infected, respectively. Worms were detected by echocardiography in 45.5% of the infected dogs. The x-rays showed that the bronchial pattern was present in 45.5% of the infected dogs and in 46.7% of the non-infected dogs. The interstitial pattern was present in 18.2% of the infected animals, in contrast to 6.7% of the non-infected dogs. The CBC results for all dogs were within the reference range, except for platelets. Although similar, the percentage of dogs with thrombocytopenia was higher among infected dogs (36.4%) than among the non-infected (6.7%). These results reinforce that due to the non-specific signs of infection, it is mandatory to perform parasitological assays when evaluating dogs presenting with cardiopulmonary signs

Influence of obesity on the clinical improvement of tracheal and bronchial collapse in dogs: a case report

Tracheal collapse is the most common progressive affection of the anterior pathways in small animals. The most common clinical symptom is a “goose honk” cough in cases of tracheal collapse and inspiratory discomfort in cases of cervical collapse. The diagnosis is based on the history, physical examination, and imaging tests, notably chest radiography and endoscopic examination. Treatment can be clinical or surgical depending on the degree of collapse. Obesity currently affects several domestic animals and predisposes them to respiratory disorders. The overlapping adipose tissue presses on the muscles of the trachea, aggravating the collapse and influencing the lung compliance and expansion. The present report describes the clinical improvement in an obese canine with tracheal and bronchial collapse after clinical management and therapeutic ration

Influence of obesity on the clinical improvement of tracheal and bronchial collapse in dogs: a case report

Tracheal collapse is the most common progressive affection of the anterior pathways in small animals. The most common clinical symptom is a “goose honk” cough in cases of tracheal collapse and inspiratory discomfort in cases of cervical collapse. The diagnosis is based on the history, physical examination, and imaging tests, notably chest radiography and endoscopic examination. Treatment can be clinical or surgical depending on the degree of collapse. Obesity currently affects several domestic animals and predisposes them to respiratory disorders. The overlapping adipose tissue presses on the muscles of the trachea, aggravating the collapse and influencing the lung compliance and expansion. The present report describes the clinical improvement in an obese canine with tracheal and bronchial collapse after clinical management and therapeutic ration

Canine heartworm: natural infection along remote coastal area of Rio de Janeiro

Dirofilaria immitis is a mosquito-borne nematode that often infects dogs worldwide and causes what is commonly referred to as heartworm disease. The infection is recognized as being more prevalent in tropical and subtropical coastal regions; however, due to recent climate changes, it has been detected in regions previously considered free of infection. The asymptomatic animals presented in this case report had their infections detected opportunistically. One was presented for a routine checkup and the other for pre-operative evaluation. In the checkup case, heartworm disease was suspected after auscultation. In the presurgical case, microfilariae were found when cytology was performed. Both dogs had D. immitis infection confirmed by antigen detection using an enzyme-linked immunosorbent assay (ELISA) test. The microfilariae were confirmed to be D. immitis. This report highlights the unsuspected finding of the infection in a region where canine heartworm disease has not been a concern. It throws light on the importance of constant surveillance of animal vector-borne diseases in areas of ecotone. Surveillance must be reinforced when natural resources are disturbed, especially in the face of global climate change

Unilateral Atrial Ectopic Rhythm in a Golden Retriever

Background: Atrial ectopic rhythm is a type of supraventricular arrhythmia, originating in two distinct points in the atrial region. In the electrocardiographic (ECG) tracing, it is represented by independent depolarizations of sinus P waves and ectopic P waves. The occurrence of this disorder is rare, and the diagnosis criteria are the presence of the described waves within the basal rhythm. In humans, there have been reports related to severe heart failure with an unfavorable prognosis. The present report aimed to describe the clinical case of a dog with unilateral atrial ectopic rhythm without any underlying cardiac disorder.Case: A 8-year-old male golden retriever was brought to a veterinary clinic for a preoperative evaluation for lipoma removal in the right forelimb. On clinical examination, the owner stated that the patient was active, with no signs of easy fatigue or cough. The canine displayed normophagy, normodipsia, normoquezia, and normouria. On physical examination, he demonstrated a lymphatic temperament with tachypnea. The temperature and capillary filling time were within the normal range, with a normokinetic pulse. Cardiac auscultation revealed a mild grade I/VI murmur in mitral focus and an 80-bpm heart rate. Respiratory auscultation revealed the presence of harshy lung sounds. The cough reflex was positive; the Piparote test, negative. The blood test showed no noticeable changes in blood count and serum biochemistry. Systemic systolic blood pressure was 120 mmHg. On radiographic examination, no evidence of heart or lung abnormalities were identified. After the clinical evaluation, an ECG examination was performed; a unilateral atrial ectopic rhythm was observed with different frequencies between atrial and ventricular rhythm and with P (164°) and P waves (80°). On echocardiographic examination, no morphological abnormalities were seen, though trivial mitral insufficiency was identified in a color Doppler study. Blood was collected to measure electrolytes to check for possible electrolytic abnormalities; the results were within the normal range. The patient was released for and remained stable throughout the procedure, maintaining the rhythm detected during the transoperatory time. Upon reassessment in a new ECG examination, the arrhythmia persisted, suggesting that a primary lesion in the atrial tissue was present.Discussion: An atrial ectopic rhythm diagnosis requires a detailed study with the aim of ruling out heart diseases that may affect the propagation of the cardiac stimulus. However, no morphological or functional abnormalities of note that justified triggering stimuli for the ectopic rhythm were observed. In addition, based on the echocardiographic evaluation, myocardial function was preserved, supporting the canine’s release for the procedure. The suspicion of hydroelectrolytic alteration and hypoxia was present after discarding structural causes, though it was discarded due to normal laboratory results. The presence of ectopic P waves was due to the non-interference in the sinus P’ waves; consequently, they were found in the sinus heart rhythm. Upon assessing the ectopic P wave frequency, the atrial rhythm frequency was higher than the heart rate, juxtaposing the different irregular intervals within the atrial cycle. The rhythm alone may explain that its severity can be linked to the physical findings. This indicated that they did not influence the presentation of ectopia since the cardiac output, controlled by the sinus rhythm part, was responsible for maintaining the rhythm and the demand of the organism; the electrical conduction system, responsible for atrial systole, represents 15-25% of the blood ejection for the ventricular filling. Patients with rhythm disorders as described need guidance and follow-up for the early detection of clinical signs resulting from the destabilization of the condition.Keywords: atrial dissociation, supraventricular arrhythmia, electrocardiogram, dogs

Conservative treatment of ventricular tumors secondary to mammary neoplasia in dog

Cardiac neoplasms are uncommon, but secondary or metastatic neoplasms are relatively frequent, with an incidence 60 times higher than the primary ones. A particularly high frequency of metastatic cardiac involvement has been observed in lung squamous cell carcinomas, urinary tract tumors, and melanomas. However, the incidence is low because of breast tumors in dogs. Cardiac tumors may be symptomatic or, more commonly, an incidental finding observed during the investigation of unrelated problems. The clinical presentation is associated with that of a disseminated neoplasm, and cardiac metastases are generally asymptomatic but should be considered in patients with a history of neoplasia who present with impaired conduction, breathlessness, cardiomegaly, or arrhythmias. The present report aimed to describe a clinical case of cardiac metastasis of breast neoplasia in a dog in which we focusedon conservative clinical treatment and the importance of investigating the incidental clinical findings