Echocardiographically guided electrophysiologic testing in pregnancy

Arrhythmias in the pregnant patient: Current concepts in evaluation and management

Maternal arrhythmias during pregnancy may jeopardize the health of both mother and fetus. The correct identification of the arrhythmia is critical in the pregnant patient. Treatment should be reserved for arrhythmias that are hemodynamically unstable or cause debilitating symptoms. When medications are deemed necessary, the physician should use as few drugs as possible at the lowest effective doses and choose drugs with a history of safe use in pregnancy. Resuscitation of a pregnant patient in cardiac arrest should be modified with regard to the normal physiologic changes of pregnancy. With careful management, most of these challenging patients will have excellent outcomes.

Bradyarrhythmias in pregnancy: a case report and review of management

We present a case of unpaced pre-existing congenital heart block in pregnancy, diagnosed for the first time in labour. Our patient was asymptomatic and was managed conservatively with temporary pacing equipment on standby. She had a post-partum cardiology follow-up and was paced in the puerperium. We discuss the aetiopathogenesis and the variable presentation patterns of bradyarrhythmia in pregnancy and the multidisciplinary approach to their management. Our recommendations combine the Advanced Life Support algorithm for treatment of bradycardia and the successful management strategies of several documented case reports in the literature.

Using Transthoracic Two-Dimensional Echocardiography to Guide the Placement of Coronary Sinus Catheters: A Randomized Study

OBJECTIVE

To assess the value of transthoracic echocardiography (TTE) as an image guide in placing a coronary sinus catheter into the coronary sinus.

METHODS

Sixty consecutive patients undergoing electrophysiologic study were randomized to TTE (30 patients, "TTE group") or x-ray fluoroscopy (30 patients, "x-ray group") as an image guide to assist in the placement of a coronary sinus catheter.

RESULTS

The success rate of placing the coronary sinus catheter was 96.7% in TTE group and 100% in x-ray group (P > 0.05). The procedure duration was 5.8 +/- 5.7 minutes in TTE group and 5.9 +/- 3.3 minutes in x-ray group (P > 0.05), The x-ray exposure time was 0.15 +/- 0 minute in TTE group and 4.2 +/- 2.8 minutes in x-ray group (P < 0.0001).

CONCLUSION

Using TTE as an image guide, coronary sinus cannulation is feasible and as rapid as standard x-ray fluoroscopy, without the radiation risk.

Transseptal left heart catheterisation guided by intracardiac echocardiography

OBJECTIVE

To develop a novel approach of transseptal puncture guided by intracardiac echocardiography and to assess its efficacy.

METHODS

Transcatheter intracardiac echocardiography with a 9 MHz rotating transducer was performed to guide transseptal puncture in 12 patients (mean age 43.1 years, range 31-68) who underwent radiofrequency catheter ablation of left sided accessory pathways. Initially, the echocardiography and transseptal catheters were placed adjacent to each other in the superior vena cava and were withdrawn to the level of the fossa ovalis.

RESULTS

The successful puncture site was associated with visualisation of the fossa ovalis (12 patients, 100%) and the aorta (12 patients, 100%), tenting of the fossa (six patients, 50%), penetration of the needle visualised by the ultrasound catheter (12 patients, 100 %), and echocardiographic contrast material applied in the left atrium (12 patients, 100%). The characteristic jump of the needle onto the fossa ovalis was observed simultaneously with fluoroscopy and intracardiac ultrasound (12 patients, 100%). All procedures were successful. There were no complications associated with the transseptal procedure.

CONCLUSIONS

Intracardiac echocardiography is feasible to guide transseptal puncture. The optimal puncture site can be assessed by simultaneous detection of the characteristic downward jump of the transseptal needle onto the fossa ovalis by intracardiac ultrasound and fluoroscopy.

Emergency transvenous cardiac pacing placement using ultrasound guidance

STUDY OBJECTIVE

We describe 9 patients who underwent ultrasound-guided transvenous cardiac pacing in which ultrasonographic imaging was used to assist and confirm the placement of electrode catheters within the right ventricle.

METHODS

We prospectively enrolled consecutive patients with complete heart block who received emergency ultrasound-assisted transvenous cardiac pacing (TVCP). Emergency physicians performed both ultrasound scanning and placement of the TVCP electrodes at a busy urban teaching medical center.

RESULTS

Real-time ultrasound-guided TVCP was successful in 8 (88.9%) of the 9 patients studied. The pacing catheter was not adequately visualized in 1 patient who ultimately required placement by a cardiologist. Echocardiography was useful in identifying pacing catheter misplacement and subsequent successful repositioning in 3 patients.

CONCLUSION

Emergency physicians should be aware that ultrasound technology could be useful in assisting TVCP in the emergency department setting. Further investigation is required to adequately evaluate this modality as a new indication for ED echocardiography.

[Arrhythmias and pregnancy]

Although arrhythmias are one of the most frequent consultations during pregnancy, fortunately the majority are benign. Usually, they are well tolerated assuming they occur in patients with structurally normal hearts. However, pregnancy adds a new aspect to the so called "arrhythmia tolerance", because arrhythmia and therapy may jeopardize the fetus. For acute treatment of narrow and wide tachycardias, with few exceptions, antiarrhythmic medications appear to be safe. In addition to the relative security of drugs such as adenosine, digoxin, propranolol, procainamide and flecainide, we could use direct current countershock with no evidence of significant complications. Because no drug is absolutely safe, chronic pharmacologic therapy is best avoided during pregnancy. Finally, radiofrequency ablation could be recommended as an alternative in women with previous tachycardias who would like to become pregnant.

Doppler Echocardiography During Pregnancy: Physiological and Abnormal Findings

Despite continuous improvements in diagnostic cardiology techniques, echocardiography remains the cornerstone for noninvasive cardiovascular assessment of the pregnant woman with heart disease or suspected cardiac abnormality. Reversible physiological cardiac remodeling of pregnancy associated with changes in valve patency or transvalvular flow pattern can be suitably assessed by the complementary use of quantitative pulsed- and continuous Doppler and qualitative color Doppler technology. These techniques are also useful for a better understanding of the pathophysiology of the hemodynamic consequences of fixed valve stenosis during pregnancy with respect to the labile nature of gradients resulting from variable loading conditions as occurs during pregnancy. Recent and specific areas of clinical use including cardiac output estimation, contrast echocardiography minimizing radioscopy during cardiac catheterization, and transesophageal echocardiography for selection of patients with mitral stenosis suitable for percutaneous catheter valvotomy illustrate the large spectrum of capabilities of this versatile method during pregnancy. (ECHOCARDIOGRAPHY, Volume 13, March 1996)

Treatment of arrhythmias during pregnancy

The treatment of arrhythmias during pregnancy is complicated by concerns for fetal well-being. Although no drug is absolutely safe, most are well tolerated. Nonpharmacologic therapy includes vagal maneuvers and esophageal pacing. Temporary and permanent pacing have been used safely during pregnancy, as has direct current cardioversion. Cardiopulmonary resuscitation is complicated by concerns for the fetus, which may be viable at 25 weeks. Diagnosis of the cause of tachyarrhythmias may be enhanced by roving chest leads or esophageal recording. Both supraventricular and ventricular tachycardias may become manifest during pregnancy, and conservative management is desirable if the symptoms are mild. Supraventricular tachycardias respond acutely to adenosine. Ventricular arrhythmias during pregnancy often occur in the absence of structural heart disease and are responsive to drug therapy. The safe use of an implantable cardioverter-defibrillator has been described.