Apparatus and methods for reducing microbubbles formation during cardiac ablation

An electroporation ablation catheter, comprising:

• an elongated shaft having a distal end;
• and
• an electrode assembly coupled to the distal end, the electrode assembly comprising:
• one or more electrodes configured to generate electric fields to effect electroporation in target tissue in response to a plurality of electrical pulse sequences delivered in a plurality of therapy sections, the electrode assembly configurable in an expanded configuration to define an interior cavity;
• an ultrasound transducer configured to generate a first set of ultrasound signals during a first electrical pulse sequence of the plurality of electrical pulse sequences and generate a second set of ultrasound signals after an end of the first electrical pulse sequence and before a beginning of a second electrical pulse sequence, the second electrical pulse sequence being an electrical pulse sequence subsequent to the first electrical pulse sequence;
• and
• an internal component extending from the distal end of the shaft and disposed in the interior cavity of the electrode assembly;
• and
• wherein the ultrasound transducer is disposed on the internal component.